A075688 Pair sums are even interprimes.

4, 8, 22, 232, 596, 4016, 7277650, 1749701948

Offset

1,1

Comments

In the sequence all pair sums are even interprimes which are in A075689. Next term of the sequence (if any) a(7) > 2750000. Is this sequence infinite?

No more terms < 1.76*10^10. - David Wasserman, Apr 06 2005

Links

Table of n, a(n) for n=1..8.

Formula

a(1)=4; smallest a(n) > a(n-1): a(1)+a(n), ..., a(n-1)+a(n) all are even interprimes.

Example

a(1) = 4; a(1) + a(2) = 4 + 8 = 12 = ( 11 + 13 ) / 2, even interprime; a(1) + a(3) = 4 + 22 = 26 = ( 23 + 29 )/2, even interprime; a(2) + a(3) = 8 + 22 = 30 = ( 29 + 31 )/2, even interprime, etc.

Crossrefs

Cf. A075689.

Sequence in context: A338310 A254404 A254403 * A272563 A272152 A306483

Adjacent sequences: A075685 A075686 A075687 * A075689 A075690 A075691

Keyword

nonn

Author

Zak Seidov, Sep 25 2002

Extensions

More terms from David Wasserman, Apr 06 2005

Status

approved