

A116899


Numbers k such that (k concatenated k times) + 1 = A000461(k) + 1 is a prime number.


0




OFFSET

1,2


COMMENTS

The (probable) prime corresponding to a(4)=3022, i.e., 3022302230...3023 has 12088 digits. Next term is greater than 5000.


LINKS

Table of n, a(n) for n=1..4.
Primeform: User group for PFGW and PrimeForm programs. [There is insufficient information to determine which posting to the forum was intended. Probably not worth pursuing.  N. J. A. Sloane, Nov 10 2019]


EXAMPLE

1, 2 and 6 are terms since 1+1, 22+1 and 666666+1 are prime numbers.


CROSSREFS

Cf. A000461.
Sequence in context: A140258 A071093 A114045 * A162146 A231545 A055698
Adjacent sequences: A116896 A116897 A116898 * A116900 A116901 A116902


KEYWORD

base,hard,more,nonn


AUTHOR

Giovanni Resta, Mar 07 2006


STATUS

approved



