A240161 Numbers n such that (k!-n)/k is prime for some k.

4, 5, 7, 8, 12, 13, 15, 16, 25, 31, 33, 34, 35, 39, 42, 55, 65, 66, 77, 78, 85, 95, 102, 105, 110, 114, 121, 130, 133, 136, 138, 152, 156, 167, 169, 170, 186, 187, 203, 204, 221, 222, 232, 246, 248, 253, 255, 259, 279, 282, 290, 294, 296, 301, 318, 322, 325, 328, 329, 333, 354, 366

Offset

1,1

Comments

Numbers n such that A240160(n) is not null. - Michel Marcus, Aug 05 2014

Links

Jens Kruse Andersen, Table of n, a(n) for n = 1..300

Prog

(PARI)
a(n)=for(k=1, n, s=(k!-n)/k; if(floor(s)==s, if(ispseudoprime(s), return(k))))
n=1; while(n<500, if(a(n), print1(n, ", ")); n++)

Crossrefs

Cf. A240160, A240163.

Sequence in context: A050575 A081452 A047492 * A023629 A331840 A353438

Adjacent sequences: A240158 A240159 A240160 * A240162 A240163 A240164

Keyword

nonn

Author

Derek Orr, Aug 01 2014

Status

approved