|
Search: id:A128946
|
|
|
| A128946 |
|
Numbers n such that the largest prime < 10^n is a twin prime member. |
|
+0
1
|
| |
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
A003618(a(n)) is in A001097 (Twin primes).
|
|
EXAMPLE
|
For n=1, 10^1 = 10. 7, the greatest prime < 10, is a member of the twin prime pair 5,7.
|
|
PROGRAM
|
(PARI) g(n)=for(x=1, n, y=precprime(10^x); if(ispseudoprime(y-2), print1(x", ")))
|
|
CROSSREFS
|
Sequence in context: A070135 A067857 A027832 this_sequence A000331 A082269 A107776
Adjacent sequences: A128943 A128944 A128945 this_sequence A128947 A128948 A128949
|
|
KEYWORD
|
hard,more,nonn
|
|
AUTHOR
|
Cino Hilliard (hillcino368(AT)hotmail.com), Apr 28 2007
|
|
EXTENSIONS
|
Edited by Ray Chandler (rayjchandler(AT)sbcglobal.net), May 12 2007
a(5), a(6) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Feb 21 2008
|
|
|
Search completed in 0.002 seconds
|
