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A075688
Pair sums are even interprimes.
1
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
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 A391389
KEYWORD
nonn
AUTHOR
Zak Seidov, Sep 25 2002
EXTENSIONS
More terms from David Wasserman, Apr 06 2005
STATUS
approved