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A336490
Consider the figure made up of a row of n adjacent congruent rectangles, with diagonals of all possible rectangles drawn; a(n) is the number of interior vertices where exactly four lines cross.
3
0, 0, 1, 2, 2, 10, 22, 18, 32, 62, 100, 118, 136, 154, 274, 346, 426, 554, 698, 726, 884, 1058, 1248, 1454, 1784, 2146, 2714, 2978, 3250, 3722, 4226, 4490, 5104, 5758, 6674, 7350, 8058, 8798, 10062, 11238, 12478, 14046, 15702, 16526, 18016, 19570, 21188, 22870
OFFSET
1,4
LINKS
CROSSREFS
KEYWORD
nonn
AUTHOR
Lars Blomberg, Jul 25 2020
STATUS
approved