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 A097749 #6 Mar 25 2013 19:51:30 %S A097749 2,1,2,-1,10,6,5,-35,105,30,-63,420,-882,1260,210,1576,-10395,20790, %T A097749 -20790,17325,1890,-68409,450450,-891891,849420,-495495,270270,20790, %U A097749 4729726,-31126095,61486425,-57972915,32207175,-12297285,4729725,270270 %N A097749 Triangle T(n,k), n >= 0, 0 <= k <= n, read by rows. Let A(n,k) be the triangle in A097474. Then T(n,k) is defined by the orthogonality relations Sum_{j=i..r} T(r,j)*A(j,i)*2^-floor((j+3)/2) = 0 if i != r, = (2r+1)!/(r!*2^r) if i = r. %D A097749 H. W. Gould, Power sum identities for arbitrary symmetric arrays, SIAM J. Appl. Math., 17 (1969), 307-316. %e A097749 Triangle begins: %e A097749 2 %e A097749 1 2 %e A097749 -1 10 6 %e A097749 5 -35 105 30 %e A097749 -63 420 -882 1260 210 %Y A097749 Cf. A097474, A097801. Row sums give A001147. Is the left-hand edge A004193? %K A097749 sign,tabl,easy %O A097749 0,1 %A A097749 _N. J. A. Sloane_, Sep 21 2004 %E A097749 More terms from _Sean A. Irvine_, Mar 25 2013