No formulas or recurrences are known for the important sequences A289670 and A289671. The essence of these two sequences is captured in the six entries A290436-A290441. Any numerical properties of these would be most welcome.
Table of n, a(n) for n=0..18.
Cf. A284116, A284119, A284121, A289670-A289677, A290436-A290441.
Sequence in context: A054538 A238020 A095020 * A127825 A185100 A103420
Adjacent sequences: A290433 A290434 A290435 * A290437 A290438 A290439
N. J. A. Sloane, Aug 02 2017