a(n) = (7*n+2)*(7*n+5) = 49*n^2 + 49*n + 10.

Terms

a(0) =10a(1) =108a(2) =304a(3) =598a(4) =990a(5) =1480a(6) =2068a(7) =2754a(8) =3538a(9) =4420a(10) =5400a(11) =6478a(12) =7654a(13) =8928a(14) =10300a(15) =11770a(16) =13338a(17) =15004a(18) =16768a(19) =18630a(20) =20590a(21) =22648a(22) =24804a(23) =27058a(24) =29410a(25) =31860a(26) =34408a(27) =37054a(28) =39798a(29) =42640