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A156220 Triangle T(n, k) = (2^k/3)*Q(k, n), with T(0, 0) = -2, where Q(k, n) = (1/2)*( -Q(k-1, n) + 3*p(2, k-1)^n), and p(q, n) = Product_{j=1..n} ( (1-x^k)/(1-x) ), read by rows.

%I A156220 #10 Jan 02 2022 07:26:18
%S A156220 -2,-2,3,-2,3,-1,-2,3,-1,109,-2,3,-1,325,1555523,-2,3,-1,973,32671835,
%T A156220 49621794478165,-2,3,-1,2917,686126051,15630874866123949,
%U A156220 27744919164118690798376051,-2,3,-1,8749,14408699579,4923725784550050421,270929135785330782929292449579,2134369240927848351630724472718209102550421
%N A156220 Triangle T(n, k) = (2^k/3)*Q(k, n), with T(0, 0) = -2, where Q(k, n) = (1/2)*( -Q(k-1, n) + 3*p(2, k-1)^n), and p(q, n) = Product_{j=1..n} ( (1-x^k)/(1-x) ), read by rows.
%C A156220 A triangle sequence based on Carlitz q-Eulerian formulas (see ref).
%H A156220 G. C. Greubel, <a href="/A156220/b156220.txt">Rows n = 0..25 of the triangle, flattened</a>
%H A156220 L. Carlitz, <a href="https://projecteuclid.org/journals/duke-mathematical-journal/volume-15/issue-4/q-Bernoulli-numbers-and-polynomials/10.1215/S0012-7094-48-01588-9.short">q-Bernoulli numbers and polynomials</a>, Duke Math. J. Volume 15, Number 4 (1948), 987-1000.
%F A156220 T(n, k) = (2^k/3)*Q(k, n), with T(0, 0) = -2, where Q(k, n) = (1/2)*( -Q(k-1, n) + 3*p(2, k-1)^n), and p(q, n) = Product_{j=1..n} ( (1-q^k)/(1-q) ).
%e A156220 Triangle begins as:
%e A156220   -2;
%e A156220   -2, 3;
%e A156220   -2, 3, -1;
%e A156220   -2, 3, -1,  109;
%e A156220   -2, 3, -1,  325,   1555523;
%e A156220   -2, 3, -1,  973,  32671835,    49621794478165;
%e A156220   -2, 3, -1, 2917, 686126051, 15630874866123949, 27744919164118690798376051;
%t A156220 Q[x_, n_]:= Q[x, n]= If[n==0, 1, If[x==0, -6, (1/2)*(-Q[x-1, n] + 3*((-1)^(k-1)*QPochhammer[2, 2, x-1])^n)]];
%t A156220 T[n_, k_]:= If[n==0, -2, (2^k/3)*Q[k, n]];
%t A156220 Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten (* modified by _G. C. Greubel_, Dec 31 2021 *)
%o A156220 (Sage)
%o A156220 from sage.combinat.q_analogues import q_pochhammer
%o A156220 @CachedFunction
%o A156220 def Q(k,n):
%o A156220     if (n==0): return 1
%o A156220     elif (k==0): return -6
%o A156220     else: return (1/2)*( -Q(k-1,n) + 3*(-1)^(n*(k-1))*(q_pochhammer(k-1,2,2))^n)
%o A156220 def T(n,k): return -2 if (n==0) else (2^k/3)*Q(k,n)
%o A156220 flatten([[T(n,k) for k in (0..n)] for n in (0..10)]) # _G. C. Greubel_, Dec 31 2021
%Y A156220 Cf. A156222.
%K A156220 sign,tabl
%O A156220 0,1
%A A156220 _Roger L. Bagula_, Feb 06 2009
%E A156220 Edited by _G. C. Greubel_, Dec 31 2021