A297001 Numbers k such that A296992(k) = 2.

3, 9, 12, 18, 21, 27, 36, 40, 42, 48, 54, 72, 81, 84, 108, 120, 135, 144, 162, 168, 189, 192, 216, 243, 270, 280, 324, 336, 360, 378, 432, 448, 486, 540, 576, 640, 648, 672, 729, 756, 768, 828, 840, 864, 945, 972, 1080, 1152, 1296, 1344, 1458, 1512, 1701, 1728, 1890

Offset

1,1

Links

Table of n, a(n) for n=1..55.

Eric Weisstein's World of Mathematics, Tau Function.

Mathematica

1 + Position[Table[-1 + SelectFirst[Range[0, 5], !Divisible[RamanujanTau@ n, n^#] &], {n, 2, 2000}], 2][[All, 1]] (* Michael De Vlieger, Dec 23 2017 *)

Crossrefs

Cf. A000594, A296991, A296992.

Sequence in context: A310321 A310322 A261953 * A356220 A309394 A285564

Adjacent sequences: A296998 A296999 A297000 * A297002 A297003 A297004

Keyword

nonn

Author

Seiichi Manyama and Robert G. Wilson v, Dec 23 2017

Status

approved