login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A102747
Primes p(n) such that p(n)#+p(n+1) is divisible by p(n+2).
0
2, 7, 103, 229561, 863833
OFFSET
1,1
EXAMPLE
7 belongs to this sequence since 2*3*5*7+11 is divisible by 13.
PROG
(PARI) { isgood(p) = local(r, p2, p3); p2=nextprime(p+1); p3=nextprime(p2+1); r=Mod(1, p3); forprime(q=1, p, r*=q); r+=p2; return(r==0); }
CROSSREFS
Sequence in context: A192342 A102598 A206157 * A122524 A229165 A307329
KEYWORD
hard,more,nonn
AUTHOR
Max Alekseyev, Feb 09 2005
EXTENSIONS
863833 from Ryan Propper, Jan 07 2008
STATUS
approved