

A075688


Pair sums are even interprimes.


1




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(n1): a(1)+a(n), ..., a(n1)+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: A003684 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



