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 A287697 #12 Jun 01 2017 12:03:49 %S A287697 1,0,1,0,1,7,0,1,52,163,0,1,341,4499,8983,0,1,2246,98256,660746, %T A287697 966751,0,1,15177,2045282,35677082,155729277,179781181,0,1,104952, %U A287697 42658239,1754605504,17446464519,55690144728,53090086057 %N A287697 Triangle read by rows, (Sum_{k=0..n} T[n,k]*x^k) / (1-x)^(n+1) are generating functions of the columns of A287698. %F A287697 T(n,n) = A212856(n). %F A287697 Sum_{k=0..n} T(n,k) = A000442(n). %e A287697 Triangle starts: %e A287697 0: [1] %e A287697 1: [0, 1] %e A287697 2: [0, 1, 7] %e A287697 3: [0, 1, 52, 163] %e A287697 4: [0, 1, 341, 4499, 8983] %e A287697 5: [0, 1, 2246, 98256, 660746, 966751] %e A287697 6: [0, 1, 15177, 2045282, 35677082, 155729277, 179781181] %e A287697 7: [0, 1, 104952, 42658239, 1754605504, 17446464519, 55690144728, 53090086057] %e A287697 ... %e A287697 Let q4(x) = (x + 341*x^2 + 4499*x^3 + 8983*x^4) / (1-x)^5 then the coefficients of the series expansion of q4 are column 4 of A287698. %p A287697 A287697_row := n -> Delta(A287696_poly(n), n): # Delta defined in A287315. %p A287697 for n from 0 to 9 do A287697_row(n) od; %p A287697 A287697_eulerian := (n,x) -> add(A287697_row(n)[k+1]*x^k,k=0..n)/(1-x)^(n+1): %p A287697 for n from 0 to 4 do A287697_eulerian(n,x) od; %Y A287697 Cf. A000442, A212856, A287696, A287698. %K A287697 nonn,tabl %O A287697 0,6 %A A287697 _Peter Luschny_, May 30 2017