The number of homogeneous trisubstituted linear alkanes.

Terms

a(0) =2a(1) =6a(2) =16a(3) =36a(4) =70a(5) =122a(6) =196a(7) =296a(8) =426a(9) =590a(10) =792a(11) =1036a(12) =1326a(13) =1666a(14) =2060a(15) =2512a(16) =3026a(17) =3606a(18) =4256a(19) =4980a(20) =5782a(21) =6666a(22) =7636a(23) =8696a(24) =9850a(25) =11102a(26) =12456a(27) =13916a(28) =15486a(29) =17170