k th digit of a(n) is the number of different digits within 4 of k (not including k).

Terms

a(0) =11a(1) =111a(2) =122a(3) =212a(4) =221a(5) =1111a(6) =1222a(7) =2122a(8) =2212a(9) =2221a(10) =11111a(11) =12222a(12) =21222a(13) =22122a(14) =22212a(15) =22221a(16) =111111a(17) =122221a(18) =212222a(19) =221222a(20) =222122a(21) =222212a(22) =1111111a(23) =1222212a(24) =1222221a(25) =1333322a(26) =2122221a(27) =2212222a(28) =2221222a(29) =2222122