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A372016
G.f. A(x) satisfies A(x) = ( 1 + 4*x/(1 - x*A(x)) )^(1/2).
1
1, 2, 0, 6, -2, 38, -32, 314, -436, 3014, -5732, 31954, -74934, 363642, -983868, 4360230, -13021586, 54374950, -173933428, 698713298, -2345075002, 9189017010, -31903354068, 123070336590, -437701811100, 1672475509274, -6052049207112, 22998585552814
OFFSET
0,2
FORMULA
a(n) = Sum_{k=0..n} 4^k * binomial(n/2-k/2+1/2,k) * binomial(n-1,n-k)/(n-k+1).
PROG
(PARI) a(n) = sum(k=0, n, 4^k*binomial(n/2-k/2+1/2, k)*binomial(n-1, n-k)/(n-k+1));
CROSSREFS
Cf. A372002.
Sequence in context: A049257 A054877 A269795 * A095834 A106828 A055302
KEYWORD
sign
AUTHOR
Seiichi Manyama, Apr 15 2024
STATUS
approved