1,2

Vladeta Jovovic and Donovan Johnson, Table of n, a(n) for n = 1..1000 (first 100 terms from Vladeta Jovovic)

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, A130669.

Sequence in context: A070350 A070349 A070348 * A070340 A036124 A070339

Adjacent sequences: A130667 A130668 A130669 * A130671 A130672 A130673

nonn

Franz Vrabec, Jun 27 2007

approved