cp's OEIS Frontend

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.

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.

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%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