A350469 a(n) = hypergeom([1/2 - n/2, -n/2], [-n], -72).

1, 1, 19, 37, 379, 1045, 7867, 26677, 168283, 648469, 3677563, 15350005, 81546139, 357846229, 1825676731, 8266908853, 41129090011, 189933449365, 930257069563, 4349059158133, 21093686410267, 99376751256661, 479063106641467, 2267844629261365, 10890980548807771

Offset

0,3

Links

Andrew Howroyd, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (1,18).

Formula

a(n) ~ (1 + sqrt(73))^(n+1) / (sqrt(73) * 2^(n+1)). - Vaclav Kotesovec, Feb 18 2024

G.f.: 1/(1 - x - 18*x^2). - Andrew Howroyd, Nov 15 2025

E.g.f.: exp(x/2)*(sqrt(73)*cosh(sqrt(73)*x/2) + sinh(sqrt(73)*x/2))/sqrt(73). - Stefano Spezia, Nov 16 2025

Mathematica

Table[HypergeometricPFQ[{1/2 - n/2, -n/2}, {-n}, -72], {n, 0, 30}] (* Vaclav Kotesovec, Feb 18 2024 *)

Crossrefs

a(n) = A350470(9, n).

Sequence in context: A136063 A242979 A244931 * A111441 A144594 A287310

Adjacent sequences: A350466 A350467 A350468 * A350470 A350471 A350472

Keyword

nonn,easy

Author

Peter Luschny, Mar 19 2022

Status

approved