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 A088947 #13 Jul 29 2024 12:36:39
%S A088947 1,2,5,7,10,13,25,27,31,37,151,277,385,451,902,6314,6601,16627,24673,
%T A088947 30371,31451,32338,36058,41173,44083,44215,47322,52580,558304,659879,
%U A088947 744007,909634
%N A088947 Positions of records in A069862.
%C A088947 A069862 is the smallest k such that n divides the concatenation of numbers from (n+1) to (n+k), where (n+1) is on the most significant side.
%H A088947 Chuck Seggelin, <a href="https://web.archive.org/web/20040109233713/http://www.plastereddragon.com/maths/catcon.htm">Concatenation of Consecutive Integers</a>.
%e A088947 f(31) = 110 which exceeds f(27) = 26; f(451) = 100270; f(902) = 999100.
%t A088947 f[n_] := Block[{k = n + 1}, d = k; While[ d != 0, k++; d = Mod[d*10^Floor[ Log[10, k] + 1] + k, n]]; k - n]; a = 0; Do[b = f[n]; If[b > a, a = b; Print[n, " = ", b]], {n, 1, 34500}]
%Y A088947 Cf. A069862, A088343 (for records themselves).
%K A088947 nonn,base
%O A088947 1,2
%A A088947 _Robert G. Wilson v_, Oct 29 2003
%E A088947 More terms from _Robert G. Wilson v_ and Chuck Seggelin (chuck(AT)plastereddragon.com), Nov 14 2003
%E A088947 Edited by _Charles R Greathouse IV_, Apr 24 2010
%E A088947 a(29)-a(32) from _Michael S. Branicky_, Jul 29 2024