A065309 a(n) = prime(n) - prime(n - pi(n)).

0, 1, 3, 4, 8, 8, 12, 12, 12, 16, 18, 20, 24, 24, 24, 24, 30, 30, 36, 34, 32, 36, 40, 42, 44, 42, 42, 40, 42, 42, 56, 58, 58, 56, 60, 54, 60, 62, 64, 66, 72, 72, 82, 80, 70, 68, 80, 86, 88, 80, 82, 82, 84, 88, 90, 90, 90, 90, 96, 90, 92, 100, 110, 112, 102, 94, 108, 110, 118

Offset: 1

Author

Labos Elemer, Oct 29 2001

Keywords

• nonn

Examples

			n=100, prime(100)=541, prime(100 - Pi(100)) = p(75), p(100) - p(75) = 541 - 379 = 162 = a(100).
		

Links

• Harry J. Smith, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000040, A000720, A065308-A065310.

Programs

Mathematica

Table[Prime[n]-Prime[n-PrimePi[n]],{n,70}] (* Harvey P. Dale, Apr 23 2016 *)

PARI

a(n) = { prime(n) - prime(n - primepi(n)) } \\ Harry J. Smith, Oct 16 2009

Formula

a(n) = A000040(n) - A000040(n - A000720(n)).