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

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

a(n) = A100021(n) + 3. - Hugo Pfoertner, Nov 02 2023

a(n) = A062234(n) + A000040(n). - Anthony S. Wright, Feb 19 2024

Mathematica

ListConvolve[{-1, 3}, Prime[Range[100]]] (* Paolo Xausa, Nov 02 2023 *)

Prog

(PARI) a(n) = 3*prime(n) - prime(n+1) \\ Michel Marcus, Jun 03 2013

Crossrefs

Cf. A000040, A001043, A001223, A001748, A047235, A100021.

Sequence in context: A210249 A233771 A072606 * A105407 A222395 A222269

Adjacent sequences: A098761 A098762 A098763 * A098765 A098766 A098767

Keyword

nonn,easy

Author

Giovanni Teofilatto, Sep 30 2004

Extensions

Corrected (116 duplicated) by R. J. Mathar, Apr 22 2010

Status

approved