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A176604 Sequence defined by the recurrence formula a(n+1)=sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=0, k=0 and l=1. 4
1, 0, 1, 3, 7, 16, 39, 102, 279, 782, 2227, 6427, 18769, 55376, 164801, 494071, 1490663, 4522690, 13790171, 42234621, 129866725, 400765128, 1240796725, 3853055776, 11997619209, 37451945874, 117181432493, 367428949069 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..27.

FORMULA

G.f f: f(z)=(1-sqrt(1-4*z*(a(0)-z*a(0)^2+z*a(1)+(k+l)*z^2/(1-z)+k*z^2/(1-z)^2)))/(2*z) (k=0, l=1).

Conjecture: (n+1)*a(n) +2*(-3*n+1)*a(n-1) +(13*n-21)*a(n-2) +16*(-n+3)*a(n-3) +8*(n-4)*a(n-4)=0. - R. J. Mathar, Feb 19 2016

EXAMPLE

a(2)=(a(0)*a(1)+0)+(a(1)*a(0)+0)+1=1. a(3)=(a(0)*a(2)+0)+(a(1)^2+0)+(a(2)*a(0)+0)+1=3. a(4)=2*a(0)*a(3)+2*a(1)*a(2)+1=7.

CROSSREFS

Sequence in context: A152090 A190528 A203611 * A014140 A271788 A103439

Adjacent sequences:  A176601 A176602 A176603 * A176605 A176606 A176607

KEYWORD

easy,nonn

AUTHOR

Richard Choulet, Apr 21 2010

STATUS

approved

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Last modified February 22 21:02 EST 2018. Contains 299469 sequences. (Running on oeis4.)