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 A156222 #12 Jan 03 2022 11:13:13 %S A156222 -2,-6,9,-18,21,-15,-54,57,-51,375,-162,165,-159,1131,4666413,-486, %T A156222 489,-483,3399,98015025,148865383434975,-1458,1461,-1455,10203, %U A156222 2058376701,46892624598373299,83234757492356072395126701 %N A156222 Triangle T(n, k, q) = q^k*Q(k, n, q), with T(0, 0, q) = -2, where Q(k, n, q) = (1/q)*( -Q(k-1, n, q) + (1+q)*p(q, k-1)^n), Q(k, 0, q) = -q*(1+q)^n, p(q, n) = Product_{j=1..n} ( (1-q^k)/(1-q) ), and q = 2, read by rows. %H A156222 G. C. Greubel, <a href="/A156222/b156222.txt">Rows n = 0..19 of the triangle, flattened</a> %H A156222 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), pp. 987 - 1000. %F A156222 T(n, k, q) = q^k*Q(k, n, q), with T(0, 0, q) = -2, where Q(k, n, q) = (1/q)*( -Q(k-1, n, q) + (1+q)*p(q, k-1)^n), Q(k, 0, q) = -q*(1+q)^n, p(q, n) = Product_{j=1..n} ( (1-q^k)/(1-q) ), and q = 2. %e A156222 Triangle begins as: %e A156222 -2; %e A156222 -6, 9; %e A156222 -18, 21, -15; %e A156222 -54, 57, -51, 375; %e A156222 -162, 165, -159, 1131, 4666413; %e A156222 -486, 489, -483, 3399, 98015025, 148865383434975; %t A156222 Q[k_, n_, q_]:= Q[k, n, q]= If[n==0, 1, If[k==0, -q*(1+q)^n, (1/q)*( -Q[k-1, n, q] + (1+q)*(-1)^(n*(k-1))*QPochhammer[q,q,k-1]^n ) ]]; %t A156222 T[n_, k_, q_]:= If[n==0, -2, 2^k*Q[k, n, q]]; %t A156222 Table[T[n, k, 2], {n,0,10}, {k,0,n}]//Flatten (* modified by _G. C. Greubel_, Jan 01 2022 *) %o A156222 (Sage) %o A156222 from sage.combinat.q_analogues import q_pochhammer %o A156222 @CachedFunction %o A156222 def Q(k,n,q): %o A156222 if (n==0): return 1 %o A156222 elif (k==0): return -q*(q+1)^n %o A156222 else: return (1/q)*(-Q(k-1,n,q) + (1+q)*((-1)^(k-1)*q_pochhammer(k-1,q,q))^n) %o A156222 def T(n,k,q): return -2 if (n==0) else q^k*Q(k,n,q) %o A156222 flatten([[T(n,k,2) for k in (0..n)] for n in (0..10)]) # _G. C. Greubel_, Jan 01 2022 %Y A156222 Cf. A156220. %K A156222 sign,tabl %O A156222 0,1 %A A156222 _Roger L. Bagula_, Feb 06 2009 %E A156222 Edited by _G. C. Greubel_, Jan 01 2022