|
|
A275802
|
|
Numbers k such that (76*10^k + 167)/9 is prime.
|
|
0
|
|
|
1, 2, 4, 5, 7, 10, 16, 19, 28, 37, 41, 44, 53, 311, 490, 1252, 4360, 4732, 5575, 6833, 8878, 11171, 11396, 13079, 14903, 76615
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
For k > 1, numbers k such that the digit 8 followed by k-2 occurrences of the digit 4 followed by the digits 63 is prime (see Example section).
a(27) > 10^5.
|
|
LINKS
|
|
|
EXAMPLE
|
4 is in this sequence because (76*10^4+167)/9 = 84463 is prime.
Initial terms and associated primes:
a(1) = 1, 103;
a(2) = 2, 863;
a(3) = 4, 84463;
a(4) = 5, 844463;
a(5) = 7, 84444463, etc.
|
|
MATHEMATICA
|
Select[Range[0, 100000], PrimeQ[(76*10^#+167)/9] &]
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|