A168272 Abs(prime(prime(n))-prime(nonprime(n))).

1, 2, 2, 2, 8, 12, 22, 24, 36, 56, 66, 86, 106, 112, 122, 144, 176, 180, 224, 240, 236, 264, 292, 312, 358, 384, 396, 414, 418, 424, 512, 540, 550, 570, 630, 644, 680, 716, 734, 768, 794, 816, 872, 878, 894, 906, 984, 1092, 1096, 1100, 1122, 1140, 1150, 1218

Offset

1,2

Links

Table of n, a(n) for n=1..54.

Formula

a(n)=abs(A006450(n)-A007821(n)).

Example

a(1)=abs(3-2)=1, a(2)=abs(5-7)=2, a(3)=abs(11-13)=2, a(4)=abs(17-19)=2, a(5)=abs(31-23)=8.

Crossrefs

Cf. A000040(n-th prime), A006450((n-th prime)th prime), A007821((n-th nonprime)th prime), A018252(n-th nonprime).

Sequence in context: A221072 A339162 A360808 * A222448 A360309 A220254

Adjacent sequences: A168269 A168270 A168271 * A168273 A168274 A168275

Keyword

nonn,easy,less

Author

Juri-Stepan Gerasimov, Nov 22 2009

Extensions

Corrected (26 replaced by 36, 1218 inserted) by R. J. Mathar, Jun 04 2010

Status

approved