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 A061940 #17 Dec 05 2020 11:25:07
%S A061940 1,5,17,20,35,40,60,75,113,120,125,395,512,1204,2285,5451,5648,12736,
%T A061940 36547,113675,1073605,1466089,3610208,4076745
%N A061940 Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 11 (most significant digit on right).
%C A061940 This sequence differs from A029504 in that all least significant zeros are removed before concatenation.
%C A061940 No more terms < 10^7. - _Lars Blomberg_, Oct 20 2011
%H A061940 <a href="/index/N#concat">Index entries for related sequences</a>
%e A061940 See A061931 for example.
%t A061940 b = 11; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[c, IntegerDigits[IntegerReverse[#, b], b]], b], #] &] (* _Robert Price_, Mar 08 2020 *)
%o A061940 (PARI) lista(nn) = my(t=[]); for(k=1, nn, t=concat(t, Vecrev(digits(k/11^valuation(k, 11), 11))); if(Mod(fromdigits(t, 11), k)==0, print1(k, ", "))); \\ _Jinyuan Wang_, Dec 05 2020
%Y A061940 Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.
%K A061940 nonn,base,more
%O A061940 1,2
%A A061940 Larry Reeves (larryr(AT)acm.org), May 24 2001
%E A061940 Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002
%E A061940 a(21)-a(24) from _Lars Blomberg_, Oct 20 2011