A144306 Let a(1) = least prime p such that 18517# + p is = q(1) prime, then a(n+1) = least number such that q(n)*(q(n)+a(n+1))-1 is prime.

39317, 225283, 264517, 730843, 1328317

Offset

1,1

Comments

All primes certified using open PFGW from Primeform group with q(1)=PRIMO record prime q(5)= ((((18517#+39317) * (18517#+225282)-1) * ((18517#+39317) * (18517#+225282)+264516)-1) * (((18517#+39317) * (18517#+225282)-1) * ((18517#+39317) * (18517#+225282)+264516)+730842)-1) * ((((18517#+39317) * (18517#+225282)-1) * ((18517#+39317) * (18517#+225282)+264516)-1) * (((18517#+39317) * (18517#+225282)-1) * ((18517#+39317) * (18517#+225282)+264516)+730842)+1328316)-1 and has 127885 digits

Links

Table of n, a(n) for n=1..5.

Crossrefs

Sequence in context: A031667 A196200 A274128 * A234033 A253940 A183833

Adjacent sequences: A144303 A144304 A144305 * A144307 A144308 A144309

Keyword

hard,nonn

Author

Pierre CAMI, Sep 17 2008

Status

approved