A174215 First differences of A174214.

2, 1, 1, 1, 1, 6, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 13, 1, 1, 1, 5, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 31, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

Offset

9,1

Comments

If a(n) is odd, then it is 1 or prime; if a(n) is even, then 2+a(n)/2 is prime.

Links

Table of n, a(n) for n=9..120.

V. Shevelev, Theorems on twin primes-dual case, arXiv:0912.4006

Formula

a(n) = A174214(n+1)-A174214(n).

Crossrefs

Cf. A167495, A166945, A174214

Sequence in context: A275062 A247005 A380164 * A364457 A305567 A134744

Adjacent sequences: A174212 A174213 A174214 * A174216 A174217 A174218

Keyword

nonn,easy

Author

Vladimir Shevelev, Mar 12 2010

Extensions

Terms corrected, using the Mathar-Layman corrections of A174214, by Vladimir Shevelev, Mar 26 2010

Status

approved