|
|
A267865
|
|
Numbers n such that 49*10^n + 1 is prime.
|
|
0
|
|
|
1, 4, 5, 7, 9, 10, 18, 19, 34, 52, 71, 180, 238, 331, 370, 576, 925, 994, 1075, 1841, 2460, 2857, 6007, 6193, 10836, 18732, 58708, 72861
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
Numbers such that the digits 49 followed by n-1 occurrences of the digit 0 followed by the digit 1 is prime (see Example section).
a(29) > 10^5.
|
|
LINKS
|
|
|
EXAMPLE
|
4 is in this sequence because 49*10^4 + 1 = 490001 is prime.
Initial terms and primes associated:
a(1) = 1, 491;
a(2) = 4, 490001;
a(3) = 5, 4900001;
a(4) = 7, 490000001;
a(5) = 9, 49000000001, etc.
|
|
MATHEMATICA
|
Select[Range[0, 100000], PrimeQ[49*10^#+1] &]
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|