This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A138959 #20 Jun 24 2025 10:03:16 %S A138959 0,3,14,12,346,1518,12144,65902,370966,1405228,9288699,45012717, %T A138959 115961111,439407638,3515261104,28122088832,102906398156,365487513373, %U A138959 1398021200734,14998866871497,24623503331351,387722889932058,1194434486643964,7171290102136087 %N A138959 a(n) = 8^n mod 5^n. %t A138959 a[n_]:=PowerMod[8,n,5^n]; Array[a,24,0] (* _James C. McMahon_, Jun 23 2025 *) %o A138959 (Sage) [power_mod(8,n,5^n) for n in range(0,24)] # _Zerinvary Lajos_, Nov 28 2009 %o A138959 (PARI) a(n) = lift(Mod(8, 5^n)^n); \\ _Michel Marcus_, Feb 20 2018 %Y A138959 Cf. A000351, A001018. %K A138959 nonn %O A138959 0,2 %A A138959 _N. J. A. Sloane_, May 20 2008