OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..424
FORMULA
E.g.f.: 1/(1-Sum_{i=1..4} x^i/i!).
MAPLE
a:= proc(n) option remember; `if`(n=0, 1, add(
a(n-i)*binomial(n, i), i=1..min(n, 4)))
end:
seq(a(n), n=0..25);
# second Maple program:
a:= n-> n!*(<<0|1|0|0>, <0|0|1|0>, <0|0|0|1>, <1/24|1/6|1/2|1>>^n)[4, 4]:
seq(a(n), n=0..25);
MATHEMATICA
max = 20; CoefficientList[1/(1-Sum[x^i/i!, {i, 1, 4}]) + O[x]^(max+1), x]* Range[0, max]! (* Jean-François Alcover, May 24 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 22 2016
STATUS
approved