

A096142


Let p(0) = 1, p(k) = kth prime for k >= 1; write 2n = p(i) + p(j) with i <= j and i minimal; sequence gives i.


0



0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 2, 0, 2, 3, 0, 0, 2, 3, 0, 2, 0, 0, 2, 0, 2, 3, 0, 2, 3, 0, 0, 2, 3, 0, 2, 0, 0, 2, 3, 0, 2, 0, 2, 3, 0, 2, 3, 4, 0, 2, 0, 0, 2, 0, 0, 2, 0, 2, 3, 4, 6, 5, 6, 0, 2, 0, 2, 3, 0, 0, 2, 3, 4, 5, 0, 0, 2, 3, 0, 2, 3, 0, 2, 0, 2, 3, 0, 2, 3, 0, 0, 2, 3, 4, 5, 0, 0, 2, 0
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OFFSET

1,5


LINKS

Table of n, a(n) for n=1..99.


EXAMPLE

a(14)=3, because 28=5+23 (3rd and 9th prime) and 281, 282, 283 are not primes.


PROG

(PARI) a(n) = {tn = 2 * n; ideb = 0; ok = 0; while (! ok, if (ideb == 0, pj = tn 1, pj = tn  prime(ideb)); if (isprime(pj)  (pj == 1), ok = 1, ideb++); ); return (ideb); } \\ Michel Marcus, Aug 29 2013


CROSSREFS

Sequence in context: A281453 A079807 A116373 * A216921 A280285 A033719
Adjacent sequences: A096139 A096140 A096141 * A096143 A096144 A096145


KEYWORD

easy,nonn


AUTHOR

David Stroup, Jul 23 2004


EXTENSIONS

Terms corrected by Michel Marcus, Aug 29 2013


STATUS

approved



