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 A232800 #13 Dec 12 2013 02:59:50 %S A232800 1,1,1,1,1,1,2,2,2,2,1,2,1,2,1,6,6,3,3,6,6,1,6,3,1,3,6,1,6,6,1,3,3,1, %T A232800 6,6,1,6,3,3,1,3,3,6,1,10,10,15,5,15,15,5,15,10,10,1,10,5,15,15,1,15, %U A232800 15,5,10,1 %N A232800 Denominators written by antidiagonals of interleaved A063524(n) and A002427(n)/A006955(n). %C A232800 The numerators of Br(n)=0, 1, 1, 1/2, 0, -1/6, 0, 1/6, 0, -3/10, 0, 5/6, 0,... are in A229979(n). %C A232800 (Corresponding complementary Euler numbers Er(n): %C A232800 A198631(2n+1)/A006519(2n+2)=1/2, -1/4, 1/2, -17/8, 31/2, -691/4,... =Ef2(n). (2*n+2)*Ef2(n)=1, -1, 3, -17, 155, 2073,...=-A001469(n+1),Genocchi numbers. Er(n)=interleaved (A063524(n) and -A001469(n+1)) =0, 1, 1, -1, 0, 3, 0, -17, 0, 155,... =-A226158(n).) %e A232800 1, %e A232800 1, 1, %e A232800 1, 1, 1, %e A232800 2, 2, 2, 2, %e A232800 1, 2, 1, 2, 1, %e A232800 6, 6, 3, 3, 6, 6, etc. %e A232800 Triangle of denominators of Br(n),complementary Bernoulli numbers,written by antidiagonals (see A229979). %K A232800 nonn,frac,less %O A232800 0,7 %A A232800 _Paul Curtz_, Nov 30 2013