a(n)^3 is smallest cube containing exactly n 1's.

Terms

a(0) =1a(1) =11a(2) =58a(3) =106a(4) =671a(5) =1041a(6) =10058a(7) =22598a(8) =145981a(9) =480765a(10) =2359231a(11) =10297461a(12) =4836178a(13) =100395471a(14) =465933117a(15) =481182258a(16) =4810215701a(17) =16886336471a(18) =49303833471a(19) =103791158471a(20) =223818432208