a(n) = n * (7*binomial(n, 2) + 1).

Terms

a(0) =0a(1) =1a(2) =16a(3) =66a(4) =172a(5) =355a(6) =636a(7) =1036a(8) =1576a(9) =2277a(10) =3160a(11) =4246a(12) =5556a(13) =7111a(14) =8932a(15) =11040a(16) =13456a(17) =16201a(18) =19296a(19) =22762a(20) =26620a(21) =30891a(22) =35596a(23) =40756a(24) =46392a(25) =52525a(26) =59176a(27) =66366a(28) =74116a(29) =82447