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 A121934 #8 Dec 07 2015 09:59:24 %S A121934 1,1,5,11,59,59,419,839,2519,2519,27719,27719,360359,360359,360359, %T A121934 720719,12252239,12252239,232792559,232792559,232792559,232792559, %U A121934 5354228879,5354228879,26771144399,26771144399,80313433199,80313433199 %N A121934 Smallest positive number m such that m == i (mod i+1) for all 1<=i<=n. %F A121934 For n>=2, a(n) = A003418(n+1)-1. %Y A121934 Except for the first term, a duplicate of A070198. %Y A121934 Cf. A070198, A003418. %K A121934 nonn %O A121934 1,3 %A A121934 _Zak Seidov_, Sep 03 2006 %E A121934 Edited by _N. J. A. Sloane_, Nov 18 2007, at the suggestion of _Max Alekseyev_.