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 A205404 #11 Dec 06 2021 13:24:33 %S A205404 2,4,4,6,6,12,9,9,20,12,12,16,25,16,16,20,36,20,20,36,25,42,25,25,56, %T A205404 30,36,30,30,36,56,36,42,36,36,42,49,42,64,42,42,72,49,56,49,110,49, %U A205404 49,100,56,81,56,110,56,56,72,121,64,169,64,81,64,64,100,81,72 %N A205404 Least s(k) such that n divides s(k)-s(j) for some j < k, where s(j) = floor((j+1)^2/2)/2. %C A205404 For a guide to related sequences, see A204892. %t A205404 (See the program at A205402.) %Y A205404 Cf. A205402, A204892. %K A205404 nonn %O A205404 1,1 %A A205404 _Clark Kimberling_, Jan 27 2012 %E A205404 Definition corrected by _Clark Kimberling_, Dec 05 2021