A050192 - OEIS

A050192

a(n)=a(n-1)+a(n-2)-d, where d=a(n/2) if n is even, else d=0; 2 initial terms.

1, 0, 1, 1, 2, 2, 4, 5, 9, 12, 21, 31, 52, 79, 131, 205, 336, 532, 868, 1388, 2256, 3623, 5879, 9471, 15350, 24769, 40119, 64809, 104928, 169606, 274534, 443935, 718469, 1162068, 1880537, 3042073, 4922610, 7963815, 12886425

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,5

LINKS

Robert Israel, Table of n, a(n) for n = 1..4780

FORMULA

G.f. g(z) satisfies (1-z-z^2)*g(z) - g(z^2) = z. - Robert Israel, Jun 05 2020

MAPLE

G:= z -> z:

for i from 1 to 7 do

G:= unapply(convert(series((z-G(z^2))/(1-z-z^2), z, 2^i+1), polynom), z)

od:

seq(coeff(G(z), z, i), i=1..2^7); # Robert Israel, Jun 05 2020

CROSSREFS

Sequence in context: A088518 A001224 A102526 * A191786 A007147 A230380

Adjacent sequences: A050189 A050190 A050191 * A050193 A050194 A050195

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved