a(n) = 8*n^3 + n.

Terms

a(0) =0a(1) =9a(2) =66a(3) =219a(4) =516a(5) =1005a(6) =1734a(7) =2751a(8) =4104a(9) =5841a(10) =8010a(11) =10659a(12) =13836a(13) =17589a(14) =21966a(15) =27015a(16) =32784a(17) =39321a(18) =46674a(19) =54891a(20) =64020a(21) =74109a(22) =85206a(23) =97359a(24) =110616a(25) =125025a(26) =140634a(27) =157491a(28) =175644a(29) =195141