OFFSET
0,2
FORMULA
a(n) = (1/2) * Sum_{k=0..n} 2^k * (k+2)! * |Stirling1(n,k)|.
a(0) = 1; a(n) = 2*Sum_{k=1..n} (2*k/n + 1) * (k-1)! * binomial(n,k) * a(n-k).
MAPLE
A367475 := proc(n)
option remember ;
if n =0 then
1;
else
2*add((2*k/n + 1) * (k-1)! * binomial(n, k) * procname(n-k), k=1..n) ;
end if;
end proc:
seq(A367475(n), n=0..70) ; # R. J. Mathar, Dec 04 2023
PROG
(PARI) a(n) = sum(k=0, n, 2^k*(k+2)!*abs(stirling(n, k, 1)))/2;
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 19 2023
STATUS
approved