OFFSET
0,6
FORMULA
a(n) = Sum_{k=0..floor((n-1)/4)} (4*k+1)!/24^k * binomial(n-1,4*k) * a(n-1-4*k) for n > 4.
a(n) = n! * Sum_{k=0..floor(n/4)} binomial(n-3*k-1,k)/(24^k * (n-4*k)!). - Seiichi Manyama, Jun 08 2024
MATHEMATICA
m = 25; Range[0, m]! * CoefficientList[Series[Exp[x/(1 - x^4/24)], {x, 0, m}], x] (* Amiram Eldar, Feb 26 2022 *)
PROG
(PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(exp(x/(1-x^4/24))))
(PARI) a(n) = if(n<5, 1, sum(k=0, (n-1)\4, (4*k+1)!/24^k*binomial(n-1, 4*k)*a(n-1-4*k)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Feb 26 2022
STATUS
approved