OFFSET
1,2
COMMENTS
n divides a(n), see A085818.
PROG
(PARI) f(n) = 1 + sum(k=2, n, isprimepower(k) && !isprime(k)); \\ A085501
b(n) = {if (n==1, return (1)); my(p); if (isprimepower(n, &p) && !isprime(n), p, prime(n-f(n))); } \\ A085818
a(n) = prod(k=1, n, b(k)); \\ Michel Marcus, Jul 13 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 04 2003
STATUS
approved