A236452 Number of primes between successive Ramanujan primes.

3, 1, 2, 2, 1, 1, 1, 0, 4, 0, 1, 2, 3, 0, 2, 1, 0, 6, 0, 0, 0, 0, 2, 0, 2, 2, 0, 4, 0, 2, 0, 4, 0, 0, 1, 0, 0, 3, 3, 0, 1, 7, 0, 1, 0, 0, 0, 0, 4, 0, 0, 0, 0, 2, 4, 0, 1, 1, 2, 3, 1, 0, 0, 2, 0, 3, 6, 0, 0, 1, 2, 2, 1, 0, 0, 2, 0, 0, 0, 1, 0, 1, 0, 4, 1, 2, 3

Offset

1,1

Comments

The Ramanujan primes are given in A104272.

Links

T. D. Noe, Table of n, a(n) for n = 1..10000

Example

A104272(n) = 2, 11, 17, 29, 41, 47, 59, 67, 71, ...
a(1) = 3 because there are 3 primes between 2 and 11;
a(2) = 1 because there is 1 prime between 11 and 17;
a(3) = 2 because there are 2 primes between 17 and 29;
a(8) = 0 because there are no prime between 67 and 71.

Mathematica

lst={}; nn=1000; R=Table[0, {nn}]; s=0; Do[If[PrimeQ[k], s++]; If[PrimeQ[k/2], s--]; If[s<nn, R[[s+1]]=k], {k, Prime[3*nn]}]; R=R+1; Do[p=0; Do[If[PrimeQ[a], p++ ], {a, R[[n]]+1, R[[n+1]]-1}]; AppendTo[lst, p], {n, 100}]; lst

Crossrefs

Cf. A104272.

Sequence in context: A263211 A287571 A214316 * A376309 A056529 A087282

Adjacent sequences: A236449 A236450 A236451 * A236453 A236454 A236455

Keyword

nonn

Author

Michel Lagneau, Jan 26 2014

Status

approved