This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A055119 #12 Mar 31 2017 22:24:04 %S A055119 0,8,7,6,5,4,3,2,1,72,80,79,78,77,76,75,74,73,63,71,70,69,68,67,66,65, %T A055119 64,54,62,61,60,59,58,57,56,55,45,53,52,51,50,49,48,47,46,36,44,43,42, %U A055119 41,40,39,38,37,27,35,34,33,32,31,30,29,28,18,26,25,24,23,22,21,20,19 %N A055119 Base-9 complement of n (write n in base 9, then replace each digit with its base-9 negative). %H A055119 Alois P. Heinz, <a href="/A055119/b055119.txt">Table of n, a(n) for n = 0..6560</a> %H A055119 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %Y A055119 Cf. A004488, A048647, A055115-A055126. %Y A055119 Column k=9 of A248813. %K A055119 base,easy,nonn %O A055119 0,2 %A A055119 _Henry Bottomley_, Apr 19 2000