Self-convolution of composite numbers.

Terms

a(0) =16a(1) =48a(2) =100a(3) =168a(4) =252a(5) =360a(6) =497a(7) =660a(8) =848a(9) =1068a(10) =1326a(11) =1620a(12) =1948a(13) =2316a(14) =2723a(15) =3172a(16) =3660a(17) =4186a(18) =4762a(19) =5394a(20) =6076a(21) =6806a(22) =7585a(23) =8416a(24) =9308a(25) =10256a(26) =11260a(27) =12328a(28) =13467a(29) =14674