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 A138263 #7 Jul 09 2025 04:28:52 %S A138263 1,1,3,4,1,11,13,5,3,1,13,52,19,13,11,5,24,11,37,4,13,13,45,84,2,19, %T A138263 13,34,94,11,12,5,13,24,13,92,3,37,19,5,11,13,96,238,11,45,51,84,43,2, %U A138263 33,272,76,13,13,34,37,95,36,164,181,24,13,10,19,13,39,46,67,13,82,92,17 %N A138263 Smallest positive integer m such that n divides [10^m/m] (=A060156(m)). %C A138263 This sequence is well-defined. %H A138263 Romanian Master in Mathematics Contest, <a href="https://artofproblemsolving.com/community/c6h187665">Problem 3</a>, Bucharest, 2007. %Y A138263 Cf. A060156, A138255, A138256, A138257, A138258, A138259, A138260, A138261, A138262. %K A138263 nonn %O A138263 1,3 %A A138263 _Max Alekseyev_, Mar 09 2008