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 A115869 #5 Mar 31 2012 13:21:10 %S A115869 0,0,0,0,0,0,3,0,0,0,7,0,5,6,0,0,0,0,15,0,13,14,15,0,9,10,15,12,13,0, %T A115869 11,0,0,0,31,0,29,30,35,0,25,26,27,28,0,30,23,0,17,18,0,20,45,30,19, %U A115869 24,25,26,23,0,21,22,27,0,0,0,63,0,61,62,63,0,57,58,59,60,61,70,55,0 %N A115869 Smallest natural number m < n, such that there exists nonzero solutions to a cross-domain congruence m*i = n X i, zero if no such integer exists. %C A115869 Here * stands for ordinary multiplication and X means carryless (GF(2)[X]) multiplication (A048720). %H A115869 <a href="/index/Con#CongruCrossDomain">Index entries for sequences defined by congruent products between domains N and GF(2)[X]</a> %Y A115869 a(2n) = 2*a(n). Bisection A115870 gives the terms at odd positions. Differs from A115859 for the first time at n=23, where a(23)=15, while A115859(23)=19. Cf. A115857, A115861, A115871. %K A115869 nonn %O A115869 1,7 %A A115869 _Antti Karttunen_, Feb 07 2006