A078775 Numbers n such that n!/phi(n)!+1 is prime.

1, 2, 4, 10, 14, 33, 75, 77, 91, 136, 143, 145, 207, 481, 580, 767, 793, 841, 1720

Offset

1,2

Links

Table of n, a(n) for n=1..19.

Example

4!=24, phi(4)=2, 2!=2, 24/12+1=13

Prog

(PARI) for (n=1, 300, if (isprime(n!/eulerphi(n)!+1), print1(n", ")))

Crossrefs

Sequence in context: A053417 A082230 A236547 * A351160 A056392 A080149

Adjacent sequences: A078772 A078773 A078774 * A078776 A078777 A078778

Keyword

nonn

Author

Jon Perry, Jan 09 2003

Extensions

a(14) through a(19) from Rick L. Shepherd, Jul 10 2004

Status

approved