Concatenation of 3 or more numbers in arithmetic progression.

Terms

a(0) =111a(1) =123a(2) =135a(3) =147a(4) =159a(5) =210a(6) =222a(7) =234a(8) =246a(9) =258a(10) =321a(11) =333a(12) =345a(13) =357a(14) =369a(15) =420a(16) =432a(17) =444a(18) =456a(19) =468a(20) =531a(21) =543a(22) =555a(23) =567a(24) =579a(25) =630a(26) =642a(27) =654a(28) =666a(29) =678