Smallest numbers containing exactly n smaller numbers when written as English number names.

Terms

a(0) =0a(1) =14a(2) =21a(3) =61a(4) =414a(5) =114a(6) =122a(7) =161a(8) =162a(9) =4414a(10) =1114a(11) =1122a(12) =1223a(13) =1161a(14) =1162a(15) =1263a(16) =14162a(17) =21114a(18) =21132a(19) =21233a(20) =26666a(21) =21161a(22) =21162a(23) =21263a(24) =61273a(25) =114261a(26) =114263a(27) =121233a(28) =122334a(29) =121161