A032126 "BIK" (reversible, indistinct, unlabeled) transform of 1,2,3,4...

1, 3, 6, 15, 33, 84, 203, 525, 1330, 3465, 8955, 23400, 60957, 159471, 416702, 1090635, 2853229, 7469052, 19548759, 51177225, 133969386, 350730933, 918187991, 2403833040, 6293218393, 16475822139, 43134005238

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

C. G. Bower, Transforms (2)

Index entries for linear recurrences with constant coefficients, signature (3,2,-9,2,3,-1).

Formula

a(2n+1) = 1/2 * [F(4n+1) + F(4n) + F(2n+2) + F(2n)], with F(n) = A000045(n). - Ralf Stephan, May 04 2004

Empirical G.f.: x*(x^4-5*x^2+1) / ((x^2-3*x+1)*(x^2-x-1)*(x^2+x-1)). - Colin Barker, Dec 15 2012

Mathematica

LinearRecurrence[{3, 2, -9, 2, 3, -1}, {1, 3, 6, 15, 33, 84}, 30] (* Harvey P. Dale, Dec 14 2016 *)

Crossrefs

Sequence in context: A000599 A063832 A006647 * A190525 A032176 A173992

Adjacent sequences: A032123 A032124 A032125 * A032127 A032128 A032129

Keyword

nonn

Author

Christian G. Bower

Status

approved