1,1

Table of n, a(n) for n=1..13.

For n = 3, a(3) = 10^3 + 109 = 1109, which is prime.

Select[Range[3000], PrimeQ[10^# + 109] &]

(MAGMA) [n: n in [1..400] | IsPrime(10^n+109)];

(PARI) is(n)=ispseudoprime(10^n+109) \\ Charles R Greathouse IV, Jun 13 2017

Cf. similar sequences listed in A258932.

Sequence in context: A096058 A120265 A158328 * A060433 A216085 A219018

Adjacent sequences: A258930 A258931 A258932 * A258934 A258935 A258936

nonn,more

Vincenzo Librandi, Jun 15 2015

a(9)-a(13) from Jens Kruse Andersen, Jun 23 2015

approved