A087821 Sequence of primes P(i) such that P=(j*P(i)#)/2 - 2 and P+4 are consecutive primes, where j is odd, 0 < j < P(i+1) and P(i) denotes i-th prime.

3, 5, 5, 7, 7, 11, 13, 13, 13, 17, 17, 23, 29, 31, 31, 43, 43, 47, 53, 53, 61, 73, 83, 89, 89, 103, 131, 131, 173, 223, 227, 241, 251, 257, 311, 331, 359, 443, 523

Offset

0,1

Comments

I think I have a proof that the sequence is infinite.

Links

Table of n, a(n) for n=0..38.

Example

(3*2*3*5*7*11*13*17)/2 - 2 = 765763 and (3*2*3*5*7*11*13*17)/2 + 2 = 765767 are gap 4 primes, with j=3, i=7, P(i)=17.

Crossrefs

Cf. A087820, A087822.

Sequence in context: A242189 A302756 A305216 * A204894 A109258 A088081

Adjacent sequences: A087818 A087819 A087820 * A087822 A087823 A087824

Keyword

nonn,more

Author

Pierre CAMI, Oct 06 2003

Extensions

Edited by Ray Chandler, Oct 19 2003

Status

approved