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 A061934 #29 Feb 03 2025 13:43:57
%S A061934 1,16,19,207,350376,723792,853456,1894016
%N A061934 Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 5 (most significant digit on right, least significant zeros not written).
%C A061934 This sequence differs from A029498 in that all least significant zeros are removed before concatenation.
%C A061934 No more terms < 10^7. - _Lars Blomberg_, Oct 17 2011
%H A061934 <a href="/index/N#concat">Index entries for related sequences</a>
%e A061934 See A061931 for example.
%t A061934 cat = 0; k = 1; lst = {}; While[k < 100000, c = FromDigits@ Reverse@ IntegerDigits[k, 5]; cat = cat*10^Floor[ Log10[c] + 1] + c; If[ Mod[ FromDigits[ IntegerDigits@ cat, 5], k] == 0, AppendTo[lst, k]; Print[k]]; k++]; lst (* _Robert G. Wilson v_, Oct 17 2011 *)
%t A061934 b = 5; c = {}; Select[Range[10^4], Divisible[FromDigits[
%t A061934 c = Join[c, IntegerDigits[IntegerReverse[#, b], b]], b], #] &] (* _Robert Price_, Mar 07 2020 *)
%o A061934 (PARI) lista(nn, m=5) = 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 A061934 Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.
%K A061934 nonn,base,more
%O A061934 1,2
%A A061934 Larry Reeves (larryr(AT)acm.org), May 24 2001
%E A061934 Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002
%E A061934 a(6)-a(8) from _Lars Blomberg_, Oct 17 2011