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 A232853 #13 Dec 07 2013 07:06:58 %S A232853 1,2,2,12,12,12,24,24,24,24,720,720,720,720,720,1440,1440,1440,1440, %T A232853 1440,1440,60480,60480,60480,60480,60480,60480,60480,120960,120960, %U A232853 120960,120960,120960,120960,120960,120960,3628800 %N A232853 Repeat n+1 times A091137(n). %C A232853 A002657(n) and A091137(n) are linked to the Bernoulli numbers B n. %C A232853 Unreduced differences table of A002657(n)/A091137(n): %C A232853 1, 1/2, 5/12, 9/24, 251/720, 475/1440,... %C A232853 -1/2, -1/12, -1/24, -19/720, -27/1440,... =-A141417(n+1)/A091137(n+1), %C A232853 5/12, 1/24, 11/720, 11/1440,... %C A232853 -9/24, -19/720, -11/1440,... %C A232853 251/720, 27/1440,... %C A232853 -475/1440,... etc. %C A232853 This is an autosequence of the second kind: its inverse binomial transform is the signed sequence with the main diagonal double of the first upper diagonal. %C A232853 a(n) is the denominators written by antidiagonals. %D A232853 P. Curtz, Intégration numérique des systèmes différentiels à conditions initiales. Centre de Calcul Scientifique de l'Armement, Arcueil 1969. Pages 36 and 56. %F A232853 Repeat n+1 times A091137(n). Triangle. %e A232853 1, %e A232853 2, 2, %e A232853 12, 12, 12, %e A232853 24, 24, 24, 24, etc. %Y A232853 Cf. A195287, A002208/A002209 (reduced autosequence), A193546, A174727, A165313. %K A232853 nonn,tabl,frac,less %O A232853 0,2 %A A232853 _Paul Curtz_, Dec 01 2013