

A088987


Triples of primes between two consecutive primeindexed primes.


0



19, 23, 29, 43, 47, 53, 71, 73, 79, 163, 167, 173, 193, 197, 199, 337, 347, 349, 409, 419, 421, 521, 523, 541, 569, 571, 577, 601, 607, 613, 719, 727, 733, 971, 977, 983, 1181, 1187, 1193, 1423, 1427, 1429, 1451, 1453, 1459, 1789, 1801, 1811, 2029, 2039, 2053
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OFFSET

1,1


COMMENTS

Conjecture: There cannot be an even number total of primes between two consecutive primeindexed primes.
The conjecture is true except for the first two primeindexed primes (3 and 5), which have zero primes between them.


LINKS

Table of n, a(n) for n=1..51.


EXAMPLE

prime(prime(4)) = 17, prime(prime(5)) = 31. 19,23,29 are the "only" three primes between 17 and 31.


PROG

(PARI) pipprimes(n, m) = { for(x=1, n, c=0; p1 = prime(prime(x)); p2 = prime(prime(x+1)); forprime(y=p1+2, p22, c++); if(c==m, forprime(y=p1+2, p22, print1(y", "); ); ) ) }


CROSSREFS

Sequence in context: A286415 A305835 A019384 * A217281 A322960 A019360
Adjacent sequences: A088984 A088985 A088986 * A088988 A088989 A088990


KEYWORD

nonn


AUTHOR

Cino Hilliard, Oct 31 2003


EXTENSIONS

Edited by T. D. Noe, Apr 14 2009


STATUS

approved



