A024857 a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = (Fibonacci numbers).

1, 2, 7, 11, 27, 44, 91, 147, 278, 450, 806, 1304, 2257, 3652, 6181, 10001, 16677, 26984, 44551, 72085, 118220, 191284, 312300, 505312, 822513, 1330854, 2161907, 3498039, 5674751, 9181940

Offset

2,2

Comments

Essentially the same as A023864 with different indexing.

Links

Harvey P. Dale, Table of n, a(n) for n = 2..1000

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

Formula

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

Mathematica

CoefficientList[Series[( (-1-x^5-2x^2-x)/((x^2+x-1)(x^4+x^2-1)^2) ), {x, 0, 30}], x] (* or *) LinearRecurrence[{1, 3, -2, -1, -1, -3, 2, 1, 1, 1}, {1, 2, 7, 11, 27, 44, 91, 147, 278, 450}, 30] (* Harvey P. Dale, Dec 26 2016 *)

Crossrefs

Sequence in context: A024479 A295138 A023864 * A024481 A024591 A350711

Adjacent sequences: A024854 A024855 A024856 * A024858 A024859 A024860

Keyword

nonn

Author

Clark Kimberling

Status

approved