|
|
A294122
|
|
Numbers k such that 3*10^k + 37 is prime.
|
|
0
|
|
|
1, 2, 3, 7, 9, 15, 18, 23, 39, 147, 1104, 1158, 1466, 1514, 1935, 2149, 2203, 2553, 2730, 7169, 9807, 17684, 23828, 25824, 27207, 55679, 94964, 122977, 206927
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
For k > 1, numbers k such that the digit 3 followed by k-2 occurrences of the digit 0 followed by the digits 37 is prime (see Example section).
a(30) > 3*10^5.
|
|
LINKS
|
|
|
EXAMPLE
|
2 is in this sequence because 3*10^2 + 37 = 337 is prime.
Initial terms and associated primes:
a(1) = 1, 67;
a(2) = 2, 337;
a(3) = 3, 3037;
a(4) = 7, 30000037;
a(5) = 9, 3000000037; etc.
|
|
MATHEMATICA
|
Select[Range[0, 100000], PrimeQ[3*10^# + 37] &]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more,hard
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|