A130670 Smallest k such that phi(x) = k has exactly n even solutions.

1, 2, 4, 8, 16, 32, 24, 80, 48, 160, 72, 216, 96, 792, 360, 144, 192, 1056, 1512, 1080, 240, 288, 432, 1248, 3200, 1200, 768, 3120, 480, 576, 2496, 720, 1536, 864, 6000, 3600, 2016, 3072, 960, 3168, 3744, 1152, 11664, 2688, 2400, 2160, 9792, 1728, 6240, 9072

Offset

1,2

Links

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

Example

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.

Crossrefs

Cf. A007374, A130669.

Sequence in context: A070350 A070349 A070348 * A070340 A036124 A070339

Adjacent sequences: A130667 A130668 A130669 * A130671 A130672 A130673

Keyword

nonn

Author

Franz Vrabec, Jun 27 2007

Status

approved