

A101042


a(n) is the smallest positive d such that the nth prime is the smallest prime p for which p+d is also prime.


6



1, 2, 6, 22, 116, 88, 470, 112, 284, 242, 202, 772, 1326, 718, 1334, 1328, 2558, 1762, 1642, 2402, 3274, 1732, 7094, 9512, 7984, 5246, 12688, 10532, 9952, 16766, 7702, 60458, 9974, 25708, 5888, 13528, 10342, 25678, 62156, 69518, 76838, 37666
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OFFSET

1,2


COMMENTS

Except for n=1, A020483(a(n)/2) is the first appearance of the nth prime. It is conjectured that a(n) always exists. a(386) is the first number which must be above 10^12.


LINKS



EXAMPLE

a(3)=6 because: The 3rd prime is 5. 2+6, 3+6 is composite, 5+6 is prime. 6 is the smallest such number.


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



