Number of hexagonal regions in regular n-gon with all diagonals drawn.

Terms

a(0) =0a(1) =0a(2) =0a(3) =9a(4) =0a(5) =22a(6) =0a(7) =39a(8) =0a(9) =105a(10) =48a(11) =136a(12) =18a(13) =190a(14) =120a(15) =462a(16) =66a(17) =644a(18) =72a(19) =875a(20) =390a(21) =1296a(22) =952a(23) =1595a(24) =450a(25) =1891a(26) =1472a(27) =3201a(28) =2346a(29) =3640