We prove that there are infinitely many solutions of
where λ0 is an arbitrary real number and 6bc9adc95747cac9ac753" title="Click to view the MathML source">λ1,λ2∈R with 7673de7ecb67ec99951ec8c2c32" title="Click to view the MathML source">λ2≠0 and not in b25f075c576" title="Click to view the MathML source">Q. This improves a result by Harman.