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A050148
a(n) = T(n,n-2), array T as in A050143.
2
1, 7, 32, 160, 832, 4424, 23872, 130176, 715520, 3957448, 21998176, 122786976, 687736896, 3863423880, 21758302848, 122811081216, 694533774336, 3934558067336, 22323615621280, 126832567223712, 721500116473664
OFFSET
2,2
COMMENTS
Also T(2*n-2,n-2), array T as in A055807.
FORMULA
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
CROSSREFS
Sequence in context: A268745 A199845 A188179 * A188208 A302995 A188331
KEYWORD
nonn
STATUS
approved