

A032126


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


1



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
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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^45*x^2+1) / ((x^23*x+1)*(x^2x1)*(x^2+x1)).  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



