

A116974


Numbers n for which the sum of the proper divisors equals the product of the proper divisors.


0



2, 3, 5, 6, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS

Table of n, a(n) for n=1..60.


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@# &] (from 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

Sequence in context: A238463 A166070 A053813 * A031402 A019438 A023798
Adjacent sequences: A116971 A116972 A116973 * A116975 A116976 A116977


KEYWORD

nonn,easy


AUTHOR

Luc Stevens (lms022(AT)yahoo.com), Apr 01 2006


STATUS

approved



