A336491 Consider the figure made up of a row of n adjacent congruent rectangles, with diagonals of all possible rectangles drawn; a(n) = number of interior vertices where exactly five lines cross.

0, 0, 0, 1, 2, 2, 2, 12, 26, 20, 10, 38, 74, 118, 102, 114, 126, 178, 238, 306, 382, 466, 558, 762, 774, 778, 774, 942, 1126, 1326, 1542, 1910, 2310, 2742, 2762, 3070, 3394, 3734, 4090, 4294, 4498, 4966, 5458, 6434, 6910, 7402, 7910, 8834, 9806, 10410, 11030

Offset: 1

Author

Lars Blomberg, Jul 25 2020

Keywords

• nonn

Links

• Lars Blomberg, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A334701, A336489, A336490.