A082701 Numbers k such that (16*10^(k-1) - 61)/9 is a plateau prime.

7, 49, 103, 193, 367, 1003, 20365, 37447, 56083

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..9.

Patrick De Geest, PDP Reference Table - 171.

Makoto Kamada, Prime numbers of the form 177...771.

Index entries for primes involving repunits.

Formula

a(n) = A056248(n+1) + 2.

Example

k=7 -> (16*10^(7-1) - 61)/9 = 1777771.

Crossrefs

Cf. A082697-A082720, A056248.

Sequence in context: A343771 A008461 A043131 * A044145 A152777 A003530

Adjacent sequences: A082698 A082699 A082700 * A082702 A082703 A082704

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