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

Terms

a(0) =0a(1) =0a(2) =1a(3) =4a(4) =11a(5) =24a(6) =50a(7) =80a(8) =154a(9) =220a(10) =375a(11) =444a(12) =781a(13) =952a(14) =1456a(15) =1696a(16) =2500a(17) =2466a(18) =4029a(19) =4500a(20) =6175a(21) =6820a(22) =9086a(23) =9024a(24) =12926a(25) =13988a(26) =17875a(27) =19180a(28) =24129a(29) =21480