|
| |
|
|
A068814
|
|
Primes with a 2 followed by (possibly zero) 1's.
|
|
1
| |
|
|
2, 211, 2111, 2111111111111, 2111111111111111111, 211111111111111111111111, 2111111111111111111111111111111111111111111111111111111111, 211111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| Primes of the form (19*10^n-1)/9.
|
|
|
LINKS
| Makoto Kamada, Factorizations of 211...11
|
|
|
FORMULA
| a(n) = (19*10^A056700(n)-1)/9.
|
|
|
PROG
| (PARI) for(n=0, 200, if(isprime(2*10^n+(10^(n)-1)/9)==1, print1(2*10^n+(10^(n)-1)/9, ", ")))
|
|
|
CROSSREFS
| Cf. A056700.
Sequence in context: A106100 A167839 A107612 * A170920 A195335 A090560
Adjacent sequences: A068811 A068812 A068813 * A068815 A068816 A068817
|
|
|
KEYWORD
| nonn,changed
|
|
|
AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 07 2002
|
|
|
EXTENSIONS
| More terms from Benoit Cloitre (benoit7848c(AT)orange.fr), Mar 09 2002
Edited by Ray Chandler (rayjchandler(AT)sbcglobal.net), Feb 03 2012
|
| |
|
|
