A215238 Prime(A215237).

2, 3, 113, 1637, 2971, 44293, 305663, 1133071, 370261, 1357201, 46006769, 268119517, 291057379, 3429782117, 10502593103, 10926444583, 87241770619, 226751019497, 1901687257447

Offset: 0

Author

T. D. Noe, Oct 11 2012

Keywords

• nonn
• hard

Comments

We use offset 0 because A215237 uses that offset.

a(n) is least prime(k) such that there are exactly n primes between prime(k)/2 and prime(k+1)/2. - Peter Munn, Oct 22 2017

Crossrefs

Cf. A000040, A080192, A104380, A215237.

Programs

Mathematica

t = Table[PrimePi[Prime[n + 1]/2] - PrimePi[Prime[n]/2], {n, 100000}]; t2 = Flatten[Table[Position[t, n, 1, 1], {n, 0, 8}]]; Prime[t2]

Formula

a(n) = A000040(A215237(n)).

Extensions

a(14)-a(18) from Donovan Johnson, Oct 13 2012