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 A248826 #29 Oct 23 2014 20:49:44 %S A248826 1,0,1,0,-3,1,0,6,-8,1,0,-10,40,-15,1,0,15,-160,135,-24,1,0,-21,560, %T A248826 -945,336,-35,1,0,28,-1792,5670,-3584,700,-48,1,0,-36,5376,-30618, %U A248826 32256,-10500,1296,-63,1,0,45,-15360,153090,-258048,131250,-25920,2205,-80,1,0,-55,42240,-721710,1892352,-1443750,427680,-56595,3520,-99,1 %N A248826 Triangle read by rows: T(n,k) is the coefficient A_k in the transformation of 1 + x + x^2 + ... + x^n to the polynomial A_k*(x+k)^k for 0 <= k <= n. %C A248826 Consider the transformation 1 + x + x^2 + x^3 + ... + x^n = A_0*(x+0)^0 + A_1*(x+1)^1 + A_2*(x+2)^2 + ... + A_n*(x+n)^n. This sequence gives A_0, ... A_n as the entries in the n-th row of this triangle, starting at n = 0. %F A248826 T(n,1) = n*(n+1)*(-1)^(n+1)/2 for n > 0. %F A248826 T(n,2) = Binomial(n+1,3)*2^(n-2)*(-1)^n for n > 1. %F A248826 T(n,n-1) = 1 - n^2 for n > 0. %F A248826 T(n,n-2) = (1/2)*n*(n-2)^2*(n+1) for n > 1. %e A248826 1; %e A248826 0, 1; %e A248826 0, -3, 1; %e A248826 0, 6, -8, 1; %e A248826 0, -10, 40, -15, 1; %e A248826 0, 15, -160, 135, -24, 1; %e A248826 0, -21, 560, -945, 336, -35, 1; %e A248826 0, 28, -1792, 5670, -3584, 700, -48, 1; %e A248826 0, -36, 5376, -30618, 32256, -10500, 1296, -63, 1; %e A248826 0, 45, -15360, 153090, -258048, 131250, -25920, 2205, -80, 1; %e A248826 0, -55, 42240, -721710, 1892352, -1443750, 427680, -56595, 3520, -99, 1; %o A248826 (PARI) for(n=0,20,for(k=0,n,if(!k,if(n,print1(0,", "));if(!n,print1(1,", ")));if(k,print1(-sum(i=1,n,((-k)^(i-k-1)*i*binomial(i,k))),", ")))) %Y A248826 Cf. A001789, A000217. %K A248826 sign,tabl %O A248826 0,5 %A A248826 _Derek Orr_, Oct 15 2014