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 A290139 #14 Jul 21 2017 08:30:15
%S A290139 0,1,2,3,4,3,6,3,2,8,10,5,12,3,8,3,16,6,18,6,0,14,22,9,9,16,11,11,28,
%T A290139 18,30,3,26,3,33,2,36,3,6,34,40,26,42,0,2,26,46,17,41,43,27,24,52,42,
%U A290139 28,43,12,32,58,26,60,3,60,3,23,11,66,45,62,17,70,42,72,3
%N A290139 a(n) = A225984(n) mod n.
%H A290139 Seiichi Manyama, <a href="/A290139/b290139.txt">Table of n, a(n) for n = 1..10000</a>
%F A290139 a(p) = p - 1 for all prime p.
%t A290139 MapIndexed[Mod[#1, First@ #2] &, LinearRecurrence[{-1, 1, -1, 0, 1}, {-1, 3, -7, 11, -16}, 74]] (* _Michael De Vlieger_, Jul 21 2017, after _T. D. Noe_ at A225984 *)
%Y A290139 Cf. A000040, A225876, A225984.
%K A290139 nonn
%O A290139 1,3
%A A290139 _Seiichi Manyama_, Jul 21 2017