a(n) is the number of equivalence classes of simple, open polygonal chains consisting of two segments and with all three vertices on the lattice points of an n X n grid.

A272053

a(n) is the number of equivalence classes of simple, open polygonal chains consisting of two segments and with all three vertices on the lattice points of an n X n grid.

Terms

    a(0) =0a(1) =2a(2) =19a(3) =76a(4) =215a(5) =481a(6) =946a(7) =1691a(8) =2789a(9) =4356a(10) =6525a(11) =9397a(12) =13128a(13) =17874a(14) =23768a(15) =31071a(16) =39953a(17) =50551a(18) =63141a(19) =77947a(20) =95234a(21) =115223a(22) =138305a(23) =164501a(24) =194344a(25) =228218a(26) =266165a(27) =308688a(28) =356104a(29) =408731

External references