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=1..19.
Cf. A284116, A284119, A284121, A289670-A289677, A290436-A290441.
Sequence in context: A075780 A292515 A078666 * A006804 A052533 A268798
Adjacent sequences: A290435 A290436 A290437 * A290439 A290440 A290441
N. J. A. Sloane, Aug 02 2017