OFFSET
0,2
REFERENCES
J. Riordan, Combinatorial Identities, Wiley, 1968, p. 77.
LINKS
FORMULA
a(n) = -(6*n-3)*a(n-1) + a(n-2) for n >= 2. - Sergei N. Gladkovskii, May 17 2013
G.f.: 1/Q(0), where Q(k)= 1 - x + 3*x*(k+1)/Q(k+1); (continued fraction). - Sergei N. Gladkovskii, May 17 2013
From G. C. Greubel, Aug 14 2017: (Start)
a(n) = (1/2)_{n} * (-3)^n *hypergeometric1f1(-n; -2n; -2/3), where (a)_{n} is the Pochhammer symbol.
E.g.f.: (1+6*x)^(-1/2) * exp((sqrt(1+6*x) - 1)/3). (End)
G.f.: (1/(1-x))*hypergeometric2f0(1,1/2; - ; -6*x/(1-x)^2). - G. C. Greubel, Aug 16 2017
MAPLE
f:= gfun:-rectoproc({a(n)= -(6*n-3)*a(n-1) + a(n-2), a(0)=1, a(1)=-2}, a(n), remember):
map(f, [$0..50]); # Robert Israel, Aug 16 2017
MATHEMATICA
Table[Pochhammer[1/2, n]*(-6)^n*Hypergeometric1F1[0 - n, -2*n, -2/3], {n, 0, 50}] (* G. C. Greubel, Aug 14 2017 *)
PROG
(PARI) for(n=0, 50, print1(sum(k=0, n, ((n+k)!/(k! * (n-k)!))*(-3/2)^k), ", ")) \\ G. C. Greubel, Aug 14 2017
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Dec 08 2001
STATUS
approved