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 A322267 #5 Dec 09 2018 11:41:41 %S A322267 1,1,0,1,1,0,1,2,1,0,1,3,4,2,0,1,4,9,10,5,0,1,5,16,30,32,16,0,1,6,25, %T A322267 68,117,122,61,0,1,7,36,130,320,528,544,272,0,1,8,49,222,725,1684, %U A322267 2709,2770,1385,0,1,9,64,350,1440,4400,9856,15600,15872,7936,0,1,10,81,520,2597,9966,29125,63668,99657,101042,50521,0 %N A322267 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. (sec(x) + tan(x))^k. %H A322267 <a href="/index/Bo#boustrophedon">Index entries for sequences related to boustrophedon transform</a> %F A322267 E.g.f. of column k: (sec(x) + tan(x))^k. %e A322267 E.g.f. of column k: A_k(x) = 1 + k*x/1! + k^2*x^2/2! + k*(k^2 + 1)*x^3/3! + k^2*(k^2 + 4)*x^4/4! + ... %e A322267 Square array begins: %e A322267 1, 1, 1, 1, 1, 1, ... %e A322267 0, 1, 2, 3, 4, 5, ... %e A322267 0, 1, 4, 9, 16, 25, ... %e A322267 0, 2, 10, 30, 68, 130, ... %e A322267 0, 5, 32, 117, 320, 725, ... %e A322267 0, 16, 122, 528, 1684, 4400, ... %t A322267 Table[Function[k, n! SeriesCoefficient[(Sec[x] + Tan[x])^k, {x, 0, n}]][j - n], {j, 0, 11}, {n, 0, j}] // Flatten %Y A322267 Columns k=0..3 give A000007, A000111, A001250, A292758. %Y A322267 Main diagonal gives A298244. %Y A322267 Cf. A322268. %K A322267 nonn,tabl %O A322267 0,8 %A A322267 _Ilya Gutkovskiy_, Dec 01 2018