1,1

a(5) has 176 digits, a(6) has 416 digits. [Vincenzo Librandi, Dec 10 2010; Bruno Berselli, Jul 17 2012]

Table of n, a(n) for n=1..4.

Makoto Kamada, Prime numbers of the form 22...229.

Index entries for primes involving repunits

Cf. A002275, A056678 (corresponding n), A099410.

Sequence in context: A091631 A244767 A146421 * A228408 A042636 A091630

Adjacent sequences: A093398 A093399 A093400 * A093402 A093403 A093404

nonn

Rick L. Shepherd, Mar 28 2004

approved