Squares composed of digits {0,1,4}, not ending with zero.

Terms

a(0) =1a(1) =4a(2) =144a(3) =441a(4) =1444a(5) =10404a(6) =40401a(7) =1004004a(8) =1100401a(9) =4004001a(10) =100040004a(11) =114041041a(12) =400040001a(13) =414041104a(14) =10000400004a(15) =10110101401a(16) =40000400001a(17) =41011110144a(18) =141001001001a(19) =414441100441