

A079649


Numbers n such that n! + n^2 + n + 1 is prime.


1




OFFSET

1,2


LINKS

Table of n, a(n) for n=1..6.


EXAMPLE

1!+1^2+1+1 = 1+1+1+1 = 4, which is not prime. 2!+2^2+2+1 = 2+4+2+1 = 8, which is not prime. 3!+3^2+3+1 = 6+9+3+1 = 19, which is prime, so a(1)=3.


MATHEMATICA

For[i = 1, i < 1000, If[PrimeQ[Factorial[i] + i^2 + i + 1] == True, Print[i]]; i++ ]


CROSSREFS

Sequence in context: A025106 A333199 A203193 * A255401 A263811 A323194
Adjacent sequences: A079646 A079647 A079648 * A079650 A079651 A079652


KEYWORD

nonn


AUTHOR

Neil Fernandez, Jan 22 2003


STATUS

approved



