Number of inequivalent (mod D_3) ways to place 4 points on a triangular grid of side n so that they are not vertices of an equilateral triangle of any orientation.
A243143
Number of inequivalent (mod D_3) ways to place 4 points on a triangular grid of side n so that they are not vertices of an equilateral triangle of any orientation.
Terms
- a(0) =1a(1) =22a(2) =170a(3) =816a(4) =2947a(5) =8765a(6) =22703a(7) =52823a(8) =113042a(9) =225817a(10) =426299a(11) =766905a(12) =1324282a(13) =2206478a(14) =3563770a(15) =5599258a(16) =8584775a(17) =12875840a(18) =18934040a(19) =27347390a(20) =38860741a(21) =54402707a(22) =75125825a(23) =102441321a(24) =138070912a(25) =184090795a(26) =242997153a(27) =317760863a(28) =411908932a(29) =529591532
External references
- oeis: A243143