OFFSET
1,4
EXAMPLE
a(6) = (6-2)(6-3)(6-5) = 12. a(7) = (7-2)(7-3)(7-5) = 40.
MATHEMATICA
a[n_] := Product[n - Prime[k], {k, 1, PrimePi[n - 1]}]; Array[a, 30] (* Amiram Eldar, Dec 01 2018 *)
PROG
(PARI) a(n) = my(mk = primepi(n-1)); prod(k=1, mk, n-prime(k)); \\ Michel Marcus, Dec 01 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Mar 19 2003
EXTENSIONS
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003
STATUS
approved