Number of acute triangles, distinct up to congruence, on a centered hexagonal grid of size n.

Terms

a(0) =0a(1) =2a(2) =14a(3) =49a(4) =134a(5) =296a(6) =580a(7) =1034a(8) =1720a(9) =2691a(10) =4043a(11) =5841a(12) =8193a(13) =11178a(14) =14935a(15) =19567a(16) =25197a(17) =31954a(18) =40006a(19) =49521a(20) =60596a(21) =73442a(22) =88238a(23) =105158a(24) =124432a(25) =146220a(26) =170802a(27) =198278a(28) =228999a(29) =263185