A082709 - OEIS

%I #17 Nov 10 2019 01:33:09

%S 3,13,31,61,117,291,633,1065,1495,5433,7363

%N Numbers k such that (35*10^(k-1) - 53)/9 is a plateau prime.

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

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

%H Patrick De Geest, <a href="http://www.worldofnumbers.com/deplat.htm#pdp383">PDP Reference Table - 383</a>.

%H Makoto Kamada, <a href="https://stdkmd.net/nrr/3/38883.htm#prime">Prime numbers of the form 388...883</a>.

%H <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.

%F a(n) = A056256(n) + 2.

%e k=13 -> (35*10^(13-1) - 53)/9 = 3888888888883.

%Y Cf. A082697-A082720, A056256.

%K nonn,base,hard,more

%O 1,1

%A _Patrick De Geest_, Apr 13 2003

%E Edited by _Ray Chandler_, Nov 05 2014