1,2

Vladeta Jovovic, Table of n, a(n) for n = 1..100

a(3)=4 because there are 3 even solutions (8, 10, 12) of phi(x)=4 and for all k<4 the number of even solutions of phi(x)=k is unequal to 3.

Cf. A007374.

Sequence in context: A070350 A070349 A070348 this_sequence A070340 A036124 A070339

Adjacent sequences: A130667 A130668 A130669 this_sequence A130671 A130672 A130673

nonn

Franz Vrabec (franz.vrabec(AT)planetuniqa.at), Jun 27 2007