A082700 Numbers k such that (15*10^(k-1) - 51)/9 is a plateau prime.

5, 13, 17, 19, 37, 53, 73, 101, 6233, 24029, 40223, 66395

Offset

1,1

Comments

Prime versus probable prime status and proofs are given in the author's table.

References

C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9.

Links

Table of n, a(n) for n=1..12.

Patrick De Geest, PDP Reference Table - 161.

Makoto Kamada, Prime numbers of the form 166...661.

Index entries for primes involving repunits.

Formula

a(n) = A056247(n+1) + 2.

Example

k=13 -> (15*10^(13-1) - 51)/9 = 1666666666661.

Prog

(PARI) is(n)=ispseudoprime(2*(10^n-1)/3-5*(10^(n-1)+1)) || ispseudoprime(15*10^(n-1)-51)/9 \\ Charles R Greathouse IV, Feb 07 2013

Crossrefs

Cf. A056247, A068647, A082697-A082720.

Sequence in context: A092218 A049092 A103666 * A212287 A174361 A226165

Adjacent sequences: A082697 A082698 A082699 * A082701 A082702 A082703

Keyword

nonn,base,more

Author

Patrick De Geest, Apr 13 2003

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

Edited by Ray Chandler, Nov 04 2014

Status

approved