A088988 Least prime that begins a run of exactly 2n-1 primes between two consecutive prime-indexed primes.

7, 19, 89, 463, 809, 1223, 619, 15727, 3767, 6907, 9109, 14197, 22109, 27103, 41057, 55009, 10937, 99559, 357829, 216649, 177797, 172213, 1040813, 327779, 375043, 219937, 423019, 1049177, 536281, 523571, 402769, 1155431, 2192123, 1792103

Offset: 1

Author

Cino Hilliard, Oct 31 2003

Keywords

• nonn

Examples

			5 and 11 are the 3rd and 5th primes; 7 begins a run of 1 primes.
17 and 31 are the 7rd and 11th primes; 19 begins a run of 3 primes.
		

Programs

PARI

pipprimes(n,m) = { for(x=1,n, c=0; p1 = prime(prime(x)); p2 = prime(prime(x+1)); forprime(y=p1+2,p2-2,c++); if(c==m, forprime(y=p1+2, p2-2, print1(y","); ); ) ) }

Formula

a(n) = prime(1 + A000230(n)) = prime(1 + prime(A038664(n))).

Extensions

Extended and edited by T. D. Noe, Apr 14 2009