# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a015121
Showing 1-1 of 1

%I A015121 #11 Apr 09 2016 10:49:27
%S A015121 1,1,1,1,-8,1,1,73,73,1,1,-656,5986,-656,1,1,5905,484210,484210,5905,
%T A015121 1,1,-53144,39226915,-352504880,39226915,-53144,1,1,478297,3177326971,
%U A015121 257015284435,257015284435,3177326971,478297,1,1,-4304672,257363962948
%N A015121 Triangle of q-binomial coefficients for q=-9.
%C A015121 May be read as a symmetric triangular (T[n,k]=T[n,n-k]; k=0,...,n; n=0,1,...) or square array (A[n,r]=A[r,n]=T[n+r,r], read by antidiagonals).  The diagonals of the former, or rows/columns of the latter, are: A000012 (k=0), A014991 (k=1), A015260 (k=2), A015277 (k=3), A015295 (k=4), A015315 (k=5), A015332 (k=6), A015349 (k=7), A015365 (k=8), A015381 (k=9), A015397 (k=10), A015414 (k=11), A015432 (k=12). - _M. F. Hasler_, Nov 05 2012
%H A015121 <a href="/index/Ga#Gaussian_binomial_coefficients">Index entries related to Gaussian binomial coefficients</a>.
%t A015121 Table[QBinomial[n, k, -9], {n, 0, 10}, {k, 0, n}] // Flatten (* _Jean-François Alcover_, Apr 09 2016 *)
%o A015121 (PARI) T015121(n, k, q=-9)=prod(i=1, k, (q^(1+n-i)-1)/(q^i-1)) \\ (Indexing is that of the triangular array: 0 <= k <= n = 0,1,2,...) - _M. F. Hasler_, Nov 04 2012
%Y A015121 Cf. analog triangles for other q: A015109 (q=-2), A015110 (q=-3), A015112 (q=-4), A015113 (q=-5), A015116 (q=-6), A015117 (q=-7), A015118 (q=-8), A015123 (q=-10), A015124 (q=-11), A015125 (q=-12), A015129 (q=-13), A015132 (q=-14), A015133 (q=-15). - _M. F. Hasler_, Nov 04 2012
%Y A015121 Cf. analog triangles for positive q=2,...,24: A022166 (q=2), A022167 (q=3), A022168, A022169, A022170, A022171, A022172, A022173, A022174 (q=10), A022175, A022176, A022177, A022178, A022179, A022180, A022181, A022182, A022183, A022184 (q=20), A022185, A022186, A022187, A022188. - _M. F. Hasler_, Nov 05 2012
%K A015121 sign,tabl,easy
%O A015121 0,5
%A A015121 _Olivier Gérard_

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE