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%I #12 Feb 13 2021 21:30:26
%S 1,7,32,160,832,4424,23872,130176,715520,3957448,21998176,122786976,
%T 687736896,3863423880,21758302848,122811081216,694533774336,
%U 3934558067336,22323615621280,126832567223712,721500116473664
%N a(n) = T(n,n-2), array T as in A050143.
%C Also T(2*n-2,n-2), array T as in A055807.
%F a(n) = Sum_{s=1..n} binomial(n,s)*binomial(s+n-4,n-3) = n*hypergeom([-n + 1, n-2], [2], -1) for n >= 3. - _Petros Hadjicostas_, Feb 13 2021
%Y Cf. A050143, A055807.
%K nonn
%O 2,2
%A _Clark Kimberling_