Iterated product of digits of n is a nonzero square.

Terms

a(0) =1a(1) =4a(2) =9a(3) =11a(4) =14a(5) =19a(6) =22a(7) =27a(8) =33a(9) =39a(10) =41a(11) =72a(12) =89a(13) =91a(14) =93a(15) =98a(16) =111a(17) =114a(18) =119a(19) =122a(20) =127a(21) =133a(22) =139a(23) =141a(24) =172a(25) =189a(26) =191a(27) =193a(28) =198a(29) =212