A290866 a(n) = number of segments (edges) in the configuration A290447(n).

0, 1, 3, 8, 20, 45, 91, 168, 285, 450, 670, 981, 1375, 1902, 2568, 3371, 4326, 5522, 6927, 8639, 10624, 12882, 15489, 18559, 22006, 25904, 30321, 35254, 40728, 46959, 53721, 61354, 69734, 78917, 89029, 100018, 111758, 124759, 138943

Offset: 1

Author

David Applegate, Aug 12 2017

Keywords

• nonn

Comments

Only edges above the line are counted. Total edges = a(n) + n - 1.

Links

• David Applegate, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A290447, A290865, A290867.

Formula

a(n) = A290447(n) + A290865(n).