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 A134409 #4 Sep 03 2022 21:32:01 %S A134409 0,1,1,0,2,0,3,3,0,5,5,0,8,0,11,11,0,16,0,21,21,0,29,29,0,40,0,51,51, %T A134409 0,67,67,0,88,0,109,109,0,138,0,167,167,0,207,207,0,258,0,309,309,0, %U A134409 376,0,443,443,0,531,531,0,640,0,749,749,0,887,887,0,1054,0,1221,1221,0,1428 %N A134409 Second differences of A006336. %C A134409 a(n) = A006336(n+2)-2*A006336(n+1)-A006336(n) = A134408(n+1)-A134408(n); %C A134409 apart from 0 same range as A006336; %C A134409 A001950(n) = Min(m: a(m) = A006336(n)). %Y A134409 Cf. A001950, A006336, A134408. %K A134409 nonn %O A134409 1,5 %A A134409 _Reinhard Zumkeller_, Oct 24 2007