A138973 a(n) = 8^n mod 7^n.

0, 1, 15, 169, 1695, 15961, 26846, 450066, 5247614, 13156907, 226316077, 680627620, 13354327932, 65310761853, 328708074010, 1951441519231, 15611532153848, 158125187800385, 101848932467045, 7328445851378156, 35829776440278962, 286638211522231696

Offset: 0

Author

N. J. A. Sloane, May 20 2008

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..1183

Crossrefs

Cf. k^n mod (k-1)^n: A002380 (k=3), A064629 (k=4), A138589 (k=5), A138649 (k=6), A139786 (k=7), this sequence (k=8), A139733 (k=9).

Cf. A000420, A001018.

Programs

Mathematica

a[n_]:=PowerMod[8,n,7^n];Array[a,22,0] (* James C. McMahon, Jun 23 2025 *)

PARI

a(n) = lift(Mod(8, 7^n)^n); \\ Michel Marcus, Feb 20 2018

Sage

[power_mod(8,n,7^n) for n in range(0,22)] # Zerinvary Lajos, Nov 28 2009