

A053706


Primes p such that between p and the next prime, 2 prime powers (A025475) occur.


1




OFFSET

1,1


COMMENTS

No other terms < 4290000000.  Jud McCranie, Jun 20 2000
There are no other terms < 2^63.  Donovan Johnson, Mar 11 2013


LINKS

Table of n, a(n) for n=1..5.


EXAMPLE

Between 7 and 11 the 2 prime powers are 8 and 9, between 23 and 29 the 2 prime powers are 25 and 27, between 113 and 127 the 2 prime powers are 121 and 125, while between 32749 and 32771 the 2 prime powers are 32761 = 181^2 and 32768 = 2^15.


PROG

(PARI) isok(p) = isprime(p) && (q=nextprime(p+1)) && (v=vector(qp, x, p+x)) && (#select(x>(isprimepower(x) && !isprime(x)), v) == 2);
lista(nn) = forprime(p=2, nn, if (isok(p), print1(p, ", "))); \\ Michel Marcus, Jul 15 2017


CROSSREFS

Cf. A025475, A053607.
Sequence in context: A096327 A267805 A154113 * A137367 A267926 A228698
Adjacent sequences: A053703 A053704 A053705 * A053707 A053708 A053709


KEYWORD

more,nonn


AUTHOR

Labos Elemer, Feb 14 2000


EXTENSIONS

Corrected by James A. Sellers, Feb 22 2000


STATUS

approved



