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

1,5

Comments

No formula or recurrence is known.

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

Links

Table of n, a(n) for n=1..43.

Crossrefs

Cf. A290447, A292104.

Column k=2 of triangle in A290867.

Sequence in context: A346761 A374714 A341134 * A373463 A290447 A360051

Adjacent sequences: A292100 A292101 A292102 * A292104 A292105 A292106

Keyword

nonn

Author

N. J. A. Sloane, Sep 14 2017

Status

approved