OFFSET
0,2
FORMULA
a(0) = 1; a(n) = n * a(n-1) + Sum_{k=1..n} 2^k * binomial(n,k) * a(n-k).
MAPLE
A367835 := proc(n)
option remember ;
if n = 0 then
1 ;
else
n*procname(n-1)+add(2^k*binomial(n, k)*procname(n-k), k=1..n) ;
end if;
end proc:
seq(A367835(n), n=0..70) ; # R. J. Mathar, Dec 04 2023
PROG
(PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=i*v[i]+sum(j=1, i, 2^j*binomial(i, j)*v[i-j+1])); v;
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Dec 02 2023
STATUS
approved