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 A159971 #2 Mar 30 2012 18:59:25 %S A159971 1,-2,1,4,-5,1,-10,19,-8,1,28,-68,43,-11,1,-84,240,-198,76,-14,1,264, %T A159971 -847,845,-427,118,-17,1,-858,3003,-3458,2140,-782,169,-20,1,2860, %U A159971 -10712,13804,-9996,4503,-1290,229,-23,1,-9724,38454,-54264,44574 %N A159971 Riordan array (2c(-x)-1, xc(-x)^3), c(x) the g.f. of A000108. %C A159971 Inverse of A159965. Row sums are A159972. %e A159971 Triangle begins %e A159971 1, %e A159971 -2, 1, %e A159971 4, -5, 1, %e A159971 -10, 19, -8, 1, %e A159971 28, -68, 43, -11, 1, %e A159971 -84, 240, -198, 76, -14, 1, %e A159971 264, -847, 845, -427, 118, -17, 1, %e A159971 -858, 3003, -3458, 2140, -782, 169, -20, 1 %K A159971 easy,sign,tabl %O A159971 0,2 %A A159971 _Paul Barry_, Apr 28 2009