The total number of different isosceles trapezoids, excluding squares, that can be drawn on an n X n square grid where the corners of each individual trapezoid lie on a lattice point.
A272459
The total number of different isosceles trapezoids, excluding squares, that can be drawn on an n X n square grid where the corners of each individual trapezoid lie on a lattice point.
Terms
- a(0) =0a(1) =1a(2) =7a(3) =18a(4) =40a(5) =71a(6) =119a(7) =180a(8) =264a(9) =365a(10) =495a(11) =646a(12) =832a(13) =1043a(14) =1295a(15) =1576a(16) =1904a(17) =2265a(18) =2679a(19) =3130a(20) =3640a(21) =4191a(22) =4807a(23) =5468a(24) =6200a(25) =6981a(26) =7839a(27) =8750a(28) =9744a(29) =10795
External references
- oeis: A272459