

A271640


Numbers k such that 3*10^k + 73 is prime.


0



1, 2, 5, 6, 13, 37, 50, 55, 71, 89, 217, 352, 355, 398, 449, 668, 742, 870, 1360, 1579, 2848, 3774, 5039, 5051, 6134, 6824, 7255, 12586, 17106, 27502, 30581, 33817, 97399, 170800, 172219, 177872
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

For k > 1, numbers such that the digit 3 followed by k2 occurrences of the digit 0 followed by the digits 73 is prime (see Example section).
a(37) > 2*10^5.


LINKS



EXAMPLE

5 is in this sequence because 3*10^5 + 73 = 300073 is prime.
Initial terms and primes associated:
a(1) = 1, 103;
a(2) = 2, 373;
a(3) = 5, 300073;
a(4) = 6, 3000073;
a(5) = 13, 30000000000073, etc.


MATHEMATICA

Select[Range[0, 100000], PrimeQ[3*10^# + 73] &]


PROG



CROSSREFS



KEYWORD

nonn,more


AUTHOR



EXTENSIONS



STATUS

approved



