A143430 a(n)=least prime == 1 mod 6 such that q(n)*(q(n)+a(n))-1 and q(n)*(q(n)+a(n))+1 are twin primes with q(i)=i-th prime == -1 mod 6.

7, 7, 43, 13, 43, 97, 43, 67, 193, 157, 31, 211, 61, 523, 73, 241, 13, 19, 97, 67, 13, 67, 157, 283, 193, 79, 157, 67, 151, 211, 67, 13, 7, 739, 109, 7, 151, 157, 73, 109, 61, 97, 223, 79, 157, 373, 109, 211, 193, 163, 67, 13, 31, 229, 19, 151, 31, 43, 31, 199, 7, 31

Offset

1,1

Links

Pierre CAMI, Table of n, a(n) for n = 1..10000

Example

q(1)=5, 5*(5+7)-1=59 prime, 59 and 61 twin primes so a(1)=7
q(2)=11, 11*(11+7)-1=197 prime, 197 and 199 twin primes so a(2)=7

Crossrefs

Cf. A143427, A143428, A143429.

Sequence in context: A286985 A151791 A022667 * A219399 A219447 A271064

Adjacent sequences: A143427 A143428 A143429 * A143431 A143432 A143433

Keyword

nonn

Author

Pierre CAMI, Aug 14 2008

Status

approved