A174215 - OEIS

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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

(list; graph; refs; listen; history; text; internal format)

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