login
A302122
Numbers k such that 3*10^k + 29 is prime.
0
1, 4, 6, 16, 17, 22, 34, 40, 46, 67, 78, 457, 642, 1037, 1615, 3607, 6270, 10945, 12221, 27606, 27623, 49645, 136829, 180852
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 29 is prime (see Example section).
a(23) > 2*10^5.
EXAMPLE
4 is in this sequence because 3*10^4 + 29 = 30029 is prime.
Initial terms and associated primes:
a(1) = 1, 59;
a(2) = 4, 30029;
a(3) = 6, 3000029;
a(4) = 16, 30000000000000029;
a(5) = 17, 300000000000000029; etc.
MATHEMATICA
Select[Range[0, 100000], PrimeQ[3*10^# + 29] &]
KEYWORD
nonn,more,hard
AUTHOR
Robert Price, Apr 01 2018
EXTENSIONS
a(23)-a(24) from Robert Price, May 11 2018
a(14)-a(15) inserted from Kamada data by Tyler Busby, Apr 15 2024
STATUS
approved