

A108251


Numbers n such that googol  n is prime.


2



797, 911, 1287, 2127, 2217, 2247, 2303, 2457, 2841, 3221, 3407, 3531, 3921, 4353, 4361, 4403, 5097, 5459, 5867, 6173, 6261, 6531, 6741, 6939, 7133, 7271, 7311, 7707, 7797, 8651, 8841, 8951, 9347, 9401, 9599, 9669, 9729, 10001, 10773, 10937, 11663
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

This sequence is finite with between 4.361969*10^97 and 4.361998*10^97 terms. Under the Riemann Hypothesis, it has 4.361971987140703159099509113229164611538757211...*10^97 terms.  Charles R Greathouse IV, Nov 23 2009
10^100a(148) and 10^100a(149) are the last twin primes less than 10^100.  T. D. Noe, Nov 03 2008


LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000
For each of the 1000 terms in the table, 10^100  a(n) was verified by the Magma Calculator as prime.  Jon E. Schoenfield, Aug 24 2009


EXAMPLE

A googol = 10^100. 10^100  797 is prime, so 797 is in the sequence.


MATHEMATICA

Rest[10^100#&/@NestList[NextPrime[#, 1]&, 10^100, 50]] (* Harvey P. Dale, Jan 23 2017 *)


PROG

(PARI) forstep(x=1, n, 2, if(isprime(10^100x), print1(x", ")))


CROSSREFS

Cf. A049014, A133282.
Sequence in context: A133274 A261657 A086393 * A108252 A188536 A252346
Adjacent sequences: A108248 A108249 A108250 * A108252 A108253 A108254


KEYWORD

easy,nonn,fini


AUTHOR

Cino Hilliard, Jun 17 2005


EXTENSIONS

Edited by Charles R Greathouse IV, Nov 23 2009


STATUS

approved



