A096142 Let p(0) = 1, p(k) = k-th prime for k >= 1; write 2n = p(i) + p(j) with i <= j and i minimal; sequence gives i.

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

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 28-1, 28-2, 28-3 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: A341793 A341773 A359288 * A216921 A344982 A359240

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