

A128946


Numbers n such that the largest prime < 10^n is a twin prime member.


0




OFFSET

1,2


COMMENTS

A003618(a(n)) is in A001097 (Twin primes).


LINKS

Table of n, a(n) for n=1..6.


EXAMPLE

For n=1, 10^1 = 10. 7, the greatest prime < 10, is a member of the twin prime pair 5,7.


PROG

(PARI) g(n)=for(x=1, n, y=precprime(10^x); if(ispseudoprime(y2), print1(x", ")))


CROSSREFS

Sequence in context: A317691 A067857 A027832 * A156219 A000331 A306155
Adjacent sequences: A128943 A128944 A128945 * A128947 A128948 A128949


KEYWORD

hard,more,nonn


AUTHOR

Cino Hilliard, Apr 28 2007


EXTENSIONS

Edited by Ray Chandler, May 12 2007
a(5), a(6) from Donovan Johnson, Feb 21 2008


STATUS

approved



