A292103 Number of points that are the intersections of exactly two semicircles in the configuration A290447(n).

0, 0, 0, 1, 5, 15, 35, 70, 123, 195, 285, 420, 586, 818, 1110, 1451, 1846, 2361, 2956, 3704, 4567, 5530, 6631, 7963, 9443, 11113, 13005, 15111, 17450, 20167, 23064, 26396, 30053, 34046, 38447, 43230, 48245, 53890, 60061, 66703, 73713, 81503, 89746

Offset: 1

Author

N. J. A. Sloane, Sep 14 2017

Keywords

• nonn

Comments

No formula or recurrence is known.

Needs a b-file (A290867 gives first 100 terms).

Crossrefs

Cf. A290447, A292104.

Column k=2 of triangle in A290867.