Composite numbers whose product of digits is 4.

Terms

a(0) =4a(1) =14a(2) =22a(3) =114a(4) =122a(5) =141a(6) =212a(7) =221a(8) =411a(9) =1114a(10) =1122a(11) =1141a(12) =1212a(13) =1221a(14) =1411a(15) =2112a(16) =2121a(17) =2211a(18) =11114a(19) =11122a(20) =11141a(21) =11212a(22) =11221a(23) =12112a(24) =12121a(25) =14111a(26) =21112a(27) =41111a(28) =111114a(29) =111122