a(n) = (3*n+1)*(5*n+1).

Terms

a(0) =1a(1) =24a(2) =77a(3) =160a(4) =273a(5) =416a(6) =589a(7) =792a(8) =1025a(9) =1288a(10) =1581a(11) =1904a(12) =2257a(13) =2640a(14) =3053a(15) =3496a(16) =3969a(17) =4472a(18) =5005a(19) =5568a(20) =6161a(21) =6784a(22) =7437a(23) =8120a(24) =8833a(25) =9576a(26) =10349a(27) =11152a(28) =11985a(29) =12848