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%I #10 Jun 18 2019 05:38:07
%S 1,2,-16,-3584,-1114112,-771751936,-68719476736,50102545854496768,
%T 4999067643975288487936,1104958199127771065681444864,
%U 363815722265501838229553819942912
%N Hankel transform of A084076.
%H G. C. Greubel, <a href="/A167435/b167435.txt">Table of n, a(n) for n = 0..50</a>
%F a(n) = 2^(n^2)*(-1)^n*Sum_{k=0..n} C(n+k,2k)*(-2)^(n-k).
%F a(n) = 2^(n^2)*[x^n](1-2*x)/(1+3*x+4*x^2) = 2^(n^2) *A247560(n).
%t a[n_] := Sum[Binomial[n + k, 2*k]*(-2)^(n - k), {k, 0, n}]; Table[2^(n^2)*(-1)^n*a[n], {n, 0, 10}] (* _G. C. Greubel_, Jun 13 2016 *)
%K easy,sign
%O 0,2
%A _Paul Barry_, Nov 03 2009