OFFSET
1,1
FORMULA
Union of 6 and A000040: the prime numbers.
MATHEMATICA
fQ[n_] := Block[{id = Most@Divisors@n}, Plus @@ id == Times @@ id]; Select[Range@300, fQ@# &] (* Robert G. Wilson v, Apr 03 2006 *)
PROG
(PARI) a(n)=if(n<5, [2, 3, 5, 6][n], prime(n+1)) \\ Charles R Greathouse IV, Aug 26 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Luc Stevens (lms022(AT)yahoo.com), Apr 01 2006
STATUS
approved