%I
%S 1,22,8,588,376,56,19656,17024,4576,384,801360,848096,313504,48256,
%T 2624,38797920,47494272,21685888,4643072,468608,17920,2181332160,
%U 2986217856,1590913920,424509952,60136448,4307456,122368,139864717440
%N Coefficient triangle of polynomials (rising powers) related to Pell number convolutions. Companion triangle is A058403.
%C The row polynomials are p(k,x) := sum(a(k,m)*x^m,m=0..k), k=0,1,2,...
%C The kth convolution of P0(n) := A000129(n+1) n >= 0, (Pell numbers starting with P0(0)=1) with itself is Pk( n) := A054456(n+k,k) = (p(k1,n)*(n+1)*2*P0(n+1) + q(k1,n)*(n+2)*P0(n))/(k!*8^k)), k=1,2,..., where the companion polynomials q(k,n) := sum(b(k,m)*n^m,m=0..k), k >= 0, are the row polynomials of triangle b(k,m)= A058403(k,m).
%H W. Lang, <a href="http://www.itp.kit.edu/~wl/EISpub/A058402_3.text">First 7 rows, also for A058403</a>.
%F Recursion for row polynomials defined in the comments: p(k, n)= 4*(n+2)*p(k1, n+1)+2*(n+2*(k+1))*p(k1, n)+(n+3)*q(k1, n); q(k, n)= 4*(n+1)*p(k1, n+1)+2*(n+2*(k+1))*q(k1, n), k >= 1.
%e k=2: P2(n)=((22+8*n)*(n+1)*2*P0(n+1)+(20+8*n)*(n+2)*P0(n))/128, cf. A054457.
%e 1; 22,8; 588,376,56; ... (lower triangular matrix a(k,m), k >= m >= 0, else 0).
%Y Cf. A000129, A054456, A058403, A0584045 (falling powers).
%K nonn,tabl
%O 0,2
%A _Wolfdieter Lang_, Dec 11 2000
%E Link and crossreferences added by _Wolfdieter Lang_, Jul 31 2002
