OFFSET
1,2
FORMULA
a(p) = 2p, for p prime.
a(n) = n * A271654(n). - Alois P. Heinz, Dec 03 2023
MAPLE
a:= n-> n*add(binomial(n-1, d-1), d=numtheory[divisors](n)):
seq(a(n), n=1..50); # Alois P. Heinz, Dec 03 2023
MATHEMATICA
Table[Sum[d*Binomial[n, d], {d, Divisors[n]}], {n, 50}]
PROG
(PARI) a(n) = sumdiv(n, d, d * binomial(n, d)); \\ Michel Marcus, Dec 03 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Dec 03 2023
STATUS
approved