Numbers having four 1's in base 10.

Terms

a(0) =1111a(1) =10111a(2) =11011a(3) =11101a(4) =11110a(5) =11112a(6) =11113a(7) =11114a(8) =11115a(9) =11116a(10) =11117a(11) =11118a(12) =11119a(13) =11121a(14) =11131a(15) =11141a(16) =11151a(17) =11161a(18) =11171a(19) =11181a(20) =11191a(21) =11211a(22) =11311a(23) =11411a(24) =11511a(25) =11611a(26) =11711a(27) =11811a(28) =11911a(29) =12111