A024877 - OEIS

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A024877

a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers >= 3), t = (Lucas numbers).

9, 12, 37, 61, 133, 214, 413, 669, 1208, 1954, 3394, 5492, 9309, 15062, 25131, 40663, 67147, 108646, 178181, 288303, 470670, 761560, 1239524, 2005592, 3257761, 5271168, 8550753

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OFFSET

2,1

LINKS

Table of n, a(n) for n=2..28.

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

FORMULA

G.f.: x^2*(-9+4*x^7+2*x^6+7*x^5+6*x^4-6*x^3+2*x^2-3*x) /((x^2+x-1)*(x^4+x^2-1)^2) [From Maksym Voznyy (voznyy(AT)mail.ru), Jul 28 2009]

MATHEMATICA

LinearRecurrence[{1, 3, -2, -1, -1, -3, 2, 1, 1, 1}, {9, 12, 37, 61, 133, 214, 413, 669, 1208, 1954}, 30] (* Harvey P. Dale, Jan 23 2017 *)

CROSSREFS

Sequence in context: A195162 A216297 A024312 * A120991 A253088 A341208

Adjacent sequences: A024874 A024875 A024876 * A024878 A024879 A024880

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved