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 A086838 #11 Mar 23 2024 13:51:41
%S A086838 3,6,9,13,35,66,115,145,297,402,491,521,1217,2166,3397,3591,4641,4829,
%T A086838 6810,6829,7978,8705,17676,21165,50722,52884,84763,121344,121482,
%U A086838 162070,358839,560596,1463827,1593475,1668394,2086707,2164032,2517791,4364421,4970661,19572673,20471839,31904004,31960445,51887007
%N A086838 Indices k where A057176(k) = 4.
%C A086838 By definition of the sequence A087045(n)+2 and A086809(n)+1 for every n > 0 are in the sequence. There are no further terms up to 200000
%C A086838 No more terms < 3870000. - _David Wasserman_, Mar 31 2005
%t A086838 a[m_] := Sum[a[j], {j, 0, Mod[a[m-1], m]}]; vv={}; Do[ a[n]=If[n==0, 1, b]; v=a[n+1]; b=v; If[v==4, vv=Insert[vv, n+1, -1]; Print[vv]], {n, 0, 200000-1}]
%Y A086838 Cf. A057176, A087045, A086809.
%K A086838 nonn
%O A086838 1,1
%A A086838 _Farideh Firoozbakht_, Aug 08 2003
%E A086838 More terms from _David Wasserman_, Mar 31 2005
%E A086838 a(39)-a(45) from _Michael S. Branicky_, Mar 23 2024