

A183184


Numbers n such that 10^(2n+1)8*10^n1 is prime.


4




OFFSET

1,2


REFERENCES

C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 199697, pp. 19.


LINKS

Table of n, a(n) for n=1..10.
Patrick De Geest, World!Of Numbers, Palindromic Wing Primes (PWP's)
Makoto Kamada, Prime numbers of the form 99...99199...99
Index entries for primes involving repunits.


FORMULA

a(n) = (A077776(n)1)/2.


MATHEMATICA

Do[If[PrimeQ[10^(2n + 1)  8*10^n  1], Print[n]], {n, 3000}]


PROG

(PARI) is(n)=ispseudoprime(10^(2*n+1)8*10^n1) \\ Charles R Greathouse IV, Jun 13 2017


CROSSREFS

Cf. A004023, A077775A077798, A107123A107127, A107648, A107649, A115073, A183174A183187.
Sequence in context: A147259 A328740 A183315 * A115785 A218926 A113835
Adjacent sequences: A183181 A183182 A183183 * A183185 A183186 A183187


KEYWORD

nonn,base


AUTHOR

Ray Chandler, Dec 28 2010


EXTENSIONS

Added one more term from PWP table, by Patrick De Geest, Nov 05 2014


STATUS

approved



