OFFSET
1,2
COMMENTS
All terms are odd because 7*(9*11+1)^n + 37 is divisible by 11.
EXAMPLE
1 is in this sequence because 7*10 + 37 = 107 is prime.
3 is not in the sequence because 7*10^3 + 37 = 31*227.
Initial terms and associated primes:
a(1) = 1: 107;
a(2) = 7: 70000037;
a(3) = 15: 7000000000000037;
a(4) = 21: 7000000000000000000037, etc.
MATHEMATICA
Select[Range[0, 3000], PrimeQ[7 10^# + 37] &]
PROG
(Magma) [n: n in [1..400] | IsPrime(7*10^n+37)];
(PARI) lista(nn) = for(n=1, nn, if(ispseudoprime(7*10^n+37), print1(n, ", "))); \\ Altug Alkan, Jul 05 2016
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Vincenzo Librandi, Jul 04 2016
EXTENSIONS
Edited by Bruno Berselli, Jul 05 2016
STATUS
approved