|
| |
|
|
A102960
|
|
Numbers n such that 2*10^n + 8*R_n - 7 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
|
|
1
|
|
|
|
0, 2, 12, 27, 44, 80, 119, 131, 275, 315, 876, 1307, 10895, 17105
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
Also numbers n such that (26*10^n-71)/9 is prime.
|
|
|
LINKS
|
Table of n, a(n) for n=1..14.
Makoto Kamada, Factorizations of 288...881.
Index entries for primes involving repunits.
|
|
|
MATHEMATICA
|
Do[ If[ PrimeQ[(26*10^n - 71)/9], Print[n]], {n, 0, 10000}]
|
|
|
CROSSREFS
|
Sequence in context: A031048 A098707 A152811 * A166151 A154149 A119201
Adjacent sequences: A102957 A102958 A102959 * A102961 A102962 A102963
|
|
|
KEYWORD
|
more,nonn
|
|
|
AUTHOR
|
Robert G. Wilson v, Dec 17 2004
|
|
|
EXTENSIONS
|
Addition of a(13)-a(14) from Kamada data by Robert Price, Dec 13 2010
|
|
|
STATUS
|
approved
|
| |
|
|
