OFFSET
1,2
LINKS
John Tyler Rascoe, Table of n, a(n) for n = 1..2000
FORMULA
a(p) = p, for p prime. - Michel Marcus, Sep 30 2016
EXAMPLE
a(6) = (6+1-1) *(6+1-2) *(6+1-3) *(6+1-6) = 6 *5 *4 *1 = 120, since the positive divisors of 6 are 1, 2, 3, 6.
MATHEMATICA
a[n_] := Times @@ ((n + 1 - # &) /@ Divisors[n]); Array[a, 40] (* Jean-François Alcover, Sep 30 2016 *)
PROG
(PARI) a(n) = my(d=divisors(n)); prod(k=1, #d, n+1-d[k]); \\ Michel Marcus, Sep 30 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Leroy Quet, Sep 01 2000
STATUS
approved