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%I #10 Jul 16 2017 11:21:23
%S 0,33,52,156,240,492,472,1072,832,1612,1540,2408,1680,4144,2296,4064,
%T 4352,5900,3592,8236,4464,9544,7712,9168,6208,15984,8812,12232,11968,
%U 17504,9464,23712,10976,21772,17440,19960
%N Number of 2 X 2 matrices having all terms in {-n,...,0,...,n} and determinant n-1.
%C For a guide to related sequences, see A210000.
%H Chai Wah Wu, <a href="/A211141/b211141.txt">Table of n, a(n) for n = 0..3000</a>
%t a = -n; b = n; z1 = 35;
%t t[n_] := t[n] = Flatten[Table[w*z - x*y, {w, a, b}, {x, a, b}, {y, a, b}, {z, a, b}]]
%t c[n_, k_] := c[n, k] = Count[t[n], k]
%t Table[c[n, n - 1], {n, 0, z1}] (* A211141 *)
%Y Cf. A210000.
%K nonn
%O 0,2
%A _Clark Kimberling_, Apr 02 2012
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