login
A253968
Numbers n such that (23*10^n - 26)/6 is prime.
1
2, 4, 6, 10, 11, 18, 29, 151, 920, 1456, 1716, 1915, 4148, 4403, 8005, 9600, 41945, 47238
OFFSET
1,1
EXAMPLE
n = 2, 4, and 6, yield (23*10^n - 26)/6 = 379, 38329, and 3833329, respectively, which are prime.
MATHEMATICA
fQ[n_] := PrimeQ[(23*10^n - 26)/6]; Select[ Range@ 10000, fQ] (* Robert G. Wilson v, Jan 28 2015 *)
PROG
(PARI) is(n)=ispseudoprime((23*10^n-26)/6) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Cf. A254005.
Sequence in context: A027435 A014666 A067852 * A102025 A309374 A226295
KEYWORD
nonn,more
AUTHOR
Hans Havermann, Jan 24 2015
STATUS
approved