OFFSET
0,3
LINKS
P. Barry, On the Central Coefficients of Bell Matrices, J. Int. Seq. 14 (2011) # 11.4.3, page 8.
FORMULA
G.f.: ((1-x)/sqrt(1-2*x+5*x^2) - 1)/(2*x).
a(n) = (-1)^n*n*A007440(n) (reversion of g.f. for Fibonacci numbers).
a(n) = -Sum_{k=0..floor(n/2)} C(n, k)*C(n-k, k+1)*(-1)^k. - Paul Barry, May 02 2005
E.g.f.: -exp(x)Bessel_I(1,2*i*x)/i, i=sqrt(-1). - Paul Barry, Feb 10 2006
-(n-1)*(n+1)*a(n) + n*(2*n-1)*a(n-1) - 5*n*(n-1)*a(n-2) = 0. - R. J. Mathar, Aug 17 2017
PROG
(PARI) {a(n)=polcoeff(((1-x)/sqrt(1-2*x+5*x^2+x^2*O(x^n))-1)/(2*x), n)}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Mar 11 2005
STATUS
approved