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 A055124 #18 Mar 31 2017 22:21:04 %S A055124 0,13,12,11,10,9,8,7,6,5,4,3,2,1,182,195,194,193,192,191,190,189,188, %T A055124 187,186,185,184,183,168,181,180,179,178,177,176,175,174,173,172,171, %U A055124 170,169,154,167,166,165,164,163,162,161,160,159,158,157,156,155,140 %N A055124 Base-14 complement of n (write n in base 14, then replace each digit with its base-14 negative). %H A055124 Reinhard Zumkeller, <a href="/A055124/b055124.txt">Table of n, a(n) for n = 0..2743</a> (2743 = 14^3 - 1) %H A055124 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A055124 (Haskell) %o A055124 a055124 0 = 0 %o A055124 a055124 n = if d == 0 then 14 * a055124 n' else 14 * a055124 n' + 14 - d %o A055124 where (n', d) = divMod n 14 %o A055124 -- _Reinhard Zumkeller_, Mar 12 2014 %Y A055124 Cf. A004488, A048647, A055115-A055126. %Y A055124 Column k=14 of A248813. %K A055124 base,easy,nonn %O A055124 0,2 %A A055124 _Henry Bottomley_, Apr 19 2000