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A337168
a(n) = (-1)^n + 2 * Sum_{k=0..n-1} a(k) * a(n-k-1).
4
1, 1, 5, 21, 105, 553, 3053, 17405, 101713, 606033, 3667797, 22485477, 139340985, 871429497, 5492959293, 34862161869, 222592918689, 1428814897825, 9215016141989, 59684122637237, 388045493943049, 2531696701375689, 16569559364596365, 108758426952823709
OFFSET
0,3
COMMENTS
Inverse binomial transform of A151374.
LINKS
Paveł Szabłowski, Beta distributions whose moment sequences are related to integer sequences listed in the OEIS, Contrib. Disc. Math. (2024) Vol. 19, No. 4, 85-109. See pp. 97-98.
FORMULA
G.f. A(x) satisfies: A(x) = 1 / (1 + x) + 2*x*A(x)^2.
G.f.: (1 - sqrt(1 - 8*x / (1 + x))) / (4*x).
E.g.f.: exp(3*x) * (BesselI(0,4*x) - BesselI(1,4*x)).
a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(n,k) * 2^k * Catalan(k).
a(n) ~ 7^(n + 3/2) / (2^(9/2) * sqrt(Pi) * n^(3/2)). - Vaclav Kotesovec, Nov 13 2021
MATHEMATICA
a[n_] := a[n] = (-1)^n + 2 Sum[a[k] a[n - k - 1], {k, 0, n - 1}]; Table[a[n], {n, 0, 23}]
Table[Sum[(-1)^(n - k) Binomial[n, k] 2^k CatalanNumber[k], {k, 0, n}], {n, 0, 23}]
Table[(-1)^n Hypergeometric2F1[1/2, -n, 2, 8], {n, 0, 23}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 28 2021
STATUS
approved