Equivalently, primes with decimal representation as n 6's with n's decimal representation concatenated. The next term is too large to include (2433 decimal digits).
Table of n, a(n) for n=1..3.
Cf. A176090 (corresponding n), A065589, A037065.
Sequence in context: A068533 A093631 A087513 * A173418 A147667 A022084
Adjacent sequences: A176269 A176270 A176271 * A176273 A176274 A176275
Rick L. Shepherd, Apr 13 2010