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 A061936 #21 Dec 05 2020 11:16:54
%S A061936 1,3,12,27,48,72,79,363,600,1277,1289,1815,15272,18492,38484,83556,
%T A061936 87312,148336,205731,222176,420900,549876,607797,624648,716064,5651851
%N A061936 Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 7 (most significant digit on right).
%C A061936 This sequence differs from A029500 in that all least significant zeros are removed before concatenation.
%C A061936 No more terms < 10^7. - _Lars Blomberg_, Oct 17 2011
%H A061936 <a href="/index/N#concat">Index entries for related sequences</a>
%e A061936 See A061931 for example.
%t A061936 b = 7; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[c, IntegerDigits[IntegerReverse[#, b], b]], b], #] &] (* _Robert Price_, Mar 07 2020 *)
%o A061936 (PARI) lista(nn, m=7) = my(s, t); for(k=1, nn, s=k/m^valuation(k, m); while(s, t=t*m+s%m; s\=m); if(t%k==0, print1(k, ", "))); \\ _Jinyuan Wang_, Dec 05 2020
%Y A061936 Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.
%K A061936 nonn,base,more
%O A061936 1,2
%A A061936 Larry Reeves (larryr(AT)acm.org), May 24 2001
%E A061936 Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002; Aug 25 2002
%E A061936 a(23)-a(26) from _Lars Blomberg_, Oct 17 2011