1,1

a(14) > 10^14.

Table of n, a(n) for n=1..13.

The 12 gaps following a(13) = 3074003451811 are 6, 6, 6, 78, 6, 6, 78, 36, 28, 66, 6, 6, and 6=T(3), 78=T(12), 36=T(8), 28=T(7) and 66=T(11).

Cf. A220697, A226768, A226840.

Sequence in context: A002680 A009395 A339513 * A331474 A093892 A104254

Adjacent sequences: A226766 A226767 A226768 * A226770 A226771 A226772

nonn

Giovanni Resta, Jun 17 2013

approved