|
|
A103049
|
|
Numbers n such that 7*10^n-3 is prime.
|
|
1
|
|
|
1, 3, 4, 6, 10, 20, 51, 138, 190, 360, 378, 393, 1384, 1594, 2759, 2868, 5395, 7494, 10491, 11199, 12190, 33594, 38256, 89169, 165916
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
Also numbers n such that 6*10^n + 9*R_n - 2 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
Do[ If[ PrimeQ[7*10^n - 3], Print[n]], {n, 0, 10000}]
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
more,nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|