OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = Sum_{k=1..n} C(n,k)*A012245(k).
EXAMPLE
a(6) = [6,15,20,15,6,1]*[1,1,0,0,0,1] = 6+15+1 = 22.
MAPLE
a:= proc(n) local k, i, s; s:=0; k:=1; i:=1; while k<=n do s:= s+ binomial(n, k); i:=i+1; k:=k*i; od; s; end: seq(a(n), n=0..40);
PROG
(Python)
from math import comb
def A143963(n):
c, i, s = 1, 1, 0
while (c:=c*i) <= n:
s += comb(n, c)
i += 1
return s # Chai Wah Wu, Jan 11 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 05 2008
STATUS
approved