A025106 a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (F(2), F(3), F(4), ...), t = (odd natural numbers).

3, 5, 17, 23, 50, 62, 119, 141, 251, 289, 496, 560, 939, 1045, 1729, 1903, 3122, 3406, 5559, 6021, 9795, 10545, 17120, 18336, 29731, 31701, 51361, 54551, 88338, 93502, 151367, 159725, 258523, 272049, 440272, 462160, 747883, 783301, 1267505, 1324815, 2143698

Offset

1,1

Links

Table of n, a(n) for n=1..41.

Index entries for linear recurrences with constant coefficients, signature (2,1,-4,3,-2,-1,4,-3,2,-1).

Formula

G.f.: x*(3-x+4*x^2-4*x^3-2*x^4-2*x^5-x^6-x^7)/ ((x-1)^2*(x^4+x^2-1)^2) [From Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009]

Mathematica

LinearRecurrence[{2, 1, -4, 3, -2, -1, 4, -3, 2, -1}, {3, 5, 17, 23, 50, 62, 119, 141, 251, 289}, 50] (* Harvey P. Dale, Sep 15 2024 *)

Crossrefs

Sequence in context: A231232 A154608 A024862 * A333199 A203193 A079649

Adjacent sequences: A025103 A025104 A025105 * A025107 A025108 A025109

Keyword

nonn

Author

Clark Kimberling

Extensions

G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.

Status

approved