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 A271698 #5 Apr 20 2016 08:36:07 %S A271698 1,1,0,0,1,0,0,2,1,0,0,2,8,1,0,0,2,28,22,1,0,0,2,72,182,52,1,0,0,2, %T A271698 164,974,864,114,1,0,0,2,352,4174,8444,3474,240,1,0,0,2,732,15782, %U A271698 61464,57194,12660,494,1,0,0,2,1496,55286,373940,660842,332528,43358,1004,1,0 %N A271698 Triangle read by rows, T(n,k) = Sum_{j=0..n} C(-j,-n)*E1(j,k), E1 the Eulerian numbers A173018, for n>=0 and 0<=k<=n. %H A271698 Peter Luschny, <a href="http://oeis.org/wiki/User:Peter_Luschny/ExtensionsOfTheBinomial">Extensions of the binomial</a> %e A271698 Triangle starts: %e A271698 1, %e A271698 1, 0, %e A271698 0, 1, 0, %e A271698 0, 2, 1, 0, %e A271698 0, 2, 8, 1, 0, %e A271698 0, 2, 28, 22, 1, 0, %e A271698 0, 2, 72, 182, 52, 1, 0, %e A271698 0, 2, 164, 974, 864, 114, 1, 0 %p A271698 A271698 := (n,k) -> add(binomial(-j,-n)*combinat:-eulerian1(j,k), j=0..n): %p A271698 seq(seq(A271698(n, k), k=0..n), n=0..10); %t A271698 <<Combinatorica` %t A271698 Flatten[Table[Sum[Binomial[-j,-n] Eulerian[j,k],{j,0,n}], {n,0,9},{k,0,n}]] %Y A271698 A000255 (row sums), compare A028296 for alternating rows sums, A145654 and A005803 (diag. n,n-2). %Y A271698 Cf. A173018. %K A271698 nonn,tabl %O A271698 0,8 %A A271698 _Peter Luschny_, Apr 12 2016