Number of segments created by diagonals of n-gon.

Terms

a(0) =0a(1) =4a(2) =15a(3) =39a(4) =84a(5) =160a(6) =279a(7) =455a(8) =704a(9) =1044a(10) =1495a(11) =2079a(12) =2820a(13) =3744a(14) =4879a(15) =6255a(16) =7904a(17) =9860a(18) =12159a(19) =14839a(20) =17940a(21) =21504a(22) =25575a(23) =30199a(24) =35424a(25) =41300a(26) =47879a(27) =55215a(28) =63364a(29) =72384