A072473 a(n) = prime(2*n) - prime(n).

1, 4, 8, 12, 18, 24, 26, 34, 38, 42, 48, 52, 60, 64, 66, 78, 80, 90, 96, 102, 108, 114, 116, 134, 132, 138, 148, 156, 162, 168, 166, 180, 180, 198, 200, 208, 216, 220, 230, 236, 242, 252, 252, 264, 266, 280, 280, 280, 294, 312, 324, 330, 336, 342, 344, 350, 350

Offset: 1

Author

Amarnath Murthy, Jun 20 2002

Keywords

• nonn

Comments

a(n) > prime(n) for n > 1. - Charles R Greathouse IV, Nov 22 2013

Sequence is not monotonic. - Zak Seidov, Feb 15 2015

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A072715.

Programs

Magma

[NthPrime(2*n) - NthPrime(n): n in [1..80]]; // Vincenzo Librandi, Feb 16 2015

Mathematica

Table[ Prime[2n] - Prime[n], {n, 1, 60}]

PARI

a(n) = prime(2*n) - prime(n); \\ Michel Marcus, Nov 22 2013

Formula

a(n) = A066066(n) + A000040(n). - Reinhard Zumkeller, Jul 25 2010

Extensions

Edited by Robert G. Wilson v and Jim Nastos, Jun 21 2002