A240161 - OEIS

%I #14 Aug 05 2014 02:34:40

%S 4,5,7,8,12,13,15,16,25,31,33,34,35,39,42,55,65,66,77,78,85,95,102,

%T 105,110,114,121,130,133,136,138,152,156,167,169,170,186,187,203,204,

%U 221,222,232,246,248,253,255,259,279,282,290,294,296,301,318,322,325,328,329,333,354,366

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

%C Numbers n such that A240160(n) is not null. - _Michel Marcus_, Aug 05 2014

%H Jens Kruse Andersen, <a href="/A240161/b240161.txt">Table of n, a(n) for n = 1..300</a>

%o (PARI)

%o a(n)=for(k=1,n,s=(k!-n)/k;if(floor(s)==s,if(ispseudoprime(s),return(k))))

%o n=1;while(n<500,if(a(n),print1(n,", "));n++)

%Y Cf. A240160, A240163.

%K nonn

%O 1,1

%A _Derek Orr_, Aug 01 2014