OFFSET
1,2
COMMENTS
Numbers k such that the digits 33 followed by k-1 occurrences of the digit 0 followed by the digit 1 is prime (see Example section).
a(32) > 10^5.
LINKS
Makoto Kamada, Search for 330w1.
EXAMPLE
5 is in this sequence because 33*10^5+1 = 3300001 is prime.
Initial terms and associated primes:
a(1) = 1, 331;
a(2) = 2, 3301;
a(3) = 5, 3300001;
a(4) = 6, 33000001;
a(5) = 7, 330000001;
a(6) = 8, 3300000001, etc.
MATHEMATICA
Select[Range[0, 100000], PrimeQ[33*10^#+1] &]
PROG
(PARI) lista(nn) = for(n=1, nn, if(ispseudoprime(33*10^n+1), print1(n, ", "))); \\ Altug Alkan, Mar 31 2016
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Robert Price, Mar 30 2016
STATUS
approved