It would be nice to have a recurrence.
Iris Anshel, Personal communication, Oct 23 2015.
Table of n, a(n) for n=2..7.
Sequence in context: A005716 A292055 A263628 * A320524 A218408 A048630
Adjacent sequences: A263626 A263627 A263628 * A263630 A263631 A263632
N. J. A. Sloane, Oct 27 2015