In this paper we first in
vestigate for what positi
ve integers
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si1.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=9027da55c12b0b6fb4d41dd79acb3a28" title="Click to view the MathML source">a,b,cclass="mathContainer hidden">class="mathCode"> e
very nonnegati
ve integer
n can be written as
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si2.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=6a5001eddc312421f4aeffc4b195d9f9" title="Click to view the MathML source">x(ax+1)+y(by+1)+z(cz+1)class="mathContainer hidden">class="mathCode"> with
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si3.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=9d208e0acc3fbc1d4cc089861c24b469" title="Click to view the MathML source">x,y,zclass="mathContainer hidden">class="mathCode"> integers. We show that
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si35.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=b7813060b454ecb1bba6541779e11f80" title="Click to view the MathML source">(a,b,c)class="mathContainer hidden">class="mathCode"> can be either of the following se
ven triples
v class="formula" id="fm0010">v class="mathml">class="mathmlsrc">ce" class="mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si5.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=e3be60a487642258bf2ab3ca3db24339">
class="imgLazyJSB inlineImage" height="16" width="437" alt="View the MathML source" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0022314X16302074-si5.gif">cript>
vertical-align:bottom" width="437" alt="View the MathML source" title="View the MathML source" src="http://origin-ars.els-cdn.com/content/image/1-s2.0-S0022314X16302074-si5.gif">cript>class="mathContainer hidden">class="mathCode">
class="temp" src="/sd/blank.gif">v>v> and
conje
cture that any triple
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si35.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=b7813060b454ecb1bba6541779e11f80" title="Click to view the MathML source">(a,b,c)class="mathContainer hidden">class="mathCode"> among
v class="formula" id="fm0020">v class="mathml">class="mathmlsrc">ce" class="mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si6.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=45177d148d34c25e3dd003cd2ba10841">
class="imgLazyJSB inlineImage" height="16" width="377" alt="View the MathML source" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0022314X16302074-si6.gif">cript>
vertical-align:bottom" width="377" alt="View the MathML source" title="View the MathML source" src="http://origin-ars.els-cdn.com/content/image/1-s2.0-S0022314X16302074-si6.gif">cript>class="mathContainer hidden">class="mathCode">
class="temp" src="/sd/blank.gif">v>v> also has the desired property. For integers
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si7.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=27825d82117c9d93eb9f38b74b7ebd4f" title="Click to view the MathML source">0⩽b⩽c⩽d⩽aclass="mathContainer hidden">class="mathCode"> with
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si50.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=2dc6b613ec861a57b4a876bec1248663" title="Click to view the MathML source">a>2class="mathContainer hidden">class="mathCode">, we pro
ve that any nonnegati
ve integer
can be written as
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si9.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=4303567edbfa7881d0b30a7cdbedf05d" title="Click to view the MathML source">x(ax+b)+y(ay+c)+z(az+d)class="mathContainer hidden">class="mathCode"> with
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si3.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=9d208e0acc3fbc1d4cc089861c24b469" title="Click to view the MathML source">x,y,zclass="mathContainer hidden">class="mathCode"> integers, if and only if the quadruple
class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si10.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=f0ae7e480986fc95477a4ab5e8fd53d7" title="Click to view the MathML source">(a,b,c,d)class="mathContainer hidden">class="mathCode"> is among
v class="formula" id="fm0030">v class="mathml">class="mathmlsrc">ce" class="mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302074&_mathId=si11.gif&_user=111111111&_pii=S0022314X16302074&_rdoc=1&_issn=0022314X&md5=7f0b76aefada4b25ae4cc9425c790968">
class="imgLazyJSB inlineImage" height="16" width="385" alt="View the MathML source" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0022314X16302074-si11.gif">cript>
vertical-align:bottom" width="385" alt="View the MathML source" title="View the MathML source" src="http://origin-ars.els-cdn.com/content/image/1-s2.0-S0022314X16302074-si11.gif">cript>class="mathContainer hidden">class="mathCode">
class="temp" src="/sd/blank.gif">v>v>