A098764 - OEIS

A098764

a(n) = 3p - q where p and q are consecutive primes.

3, 4, 8, 10, 20, 22, 32, 34, 40, 56, 56, 70, 80, 82, 88, 100, 116, 116, 130, 140, 140, 154, 160, 170, 190, 200, 202, 212, 214, 212, 250, 256, 272, 268, 296, 296, 308, 322, 328, 340, 356, 352, 380, 382, 392, 386, 410, 442, 452, 454, 460, 476, 472, 496, 508, 520

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OFFSET

1,1

COMMENTS

Except for the initial term, a(n)=={2, 4} mod 6.

Not monotonic: a(29) = 214 > 212 = a(30), a(33) = 272 > 268 = a(34), etc. - Charles R Greathouse IV, Jun 03 2013

LINKS

Paolo Xausa, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A001043(n) - 2*A001223(n).

a(n) = 3*A000040(n)-A000040(n+1) = A001748(n)-A000040(n+1) = A001747(n+1)-A001223(n). - R. J. Mathar, Apr 22 2010

a(n) ~ 2n log n. - Charles R Greathouse IV, Jun 03 2013