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 A338252 #9 Oct 20 2020 19:01:22 %S A338252 0,1,2,4,3,5,6,10,9,7,8,16,15,17,18,14,13,11,12,20,19,21,22,26,25,23, %T A338252 24,40,39,41,42,38,37,35,36,28,27,29,30,34,33,31,32,64,63,65,66,62,61, %U A338252 59,60,68,67,69,70,74,73,71,72,56,55,57,58,54,53,51,52,44 %N A338252 Nonpositive values in A317050, in order of appearance and negated. %C A338252 This sequence is a permutation of the nonnegative integers, with inverse A338254 (the offset has been set to 0 so as to have a permutation). %H A338252 Rémy Sigrist, <a href="/A338252/b338252.txt">Table of n, a(n) for n = 0..10922</a> %H A338252 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A338252 a(n) = -A317050(A053754(n+1)) for any n >= 0. %F A338252 a(n) = n iff n belongs to A136324. %e A338252 A338251 = 0, 1, -1, -2, 2, 3, 5, 4, -4, -3, -5, -6, -10, -9, -7, -8, ... %e A338252 We keep: 0, 1, 2, 4, 3, 5, 6, 10, 9, 7, 8, ... %o A338252 (PARI) A317050(n) = fromdigits(binary(bitxor(n, n>>1)), -2) %o A338252 print (-select(v -> v<=0, apply(A317050, [0..152]))) %Y A338252 Cf. A053754, A136324, A317050, A338251, A338254. %K A338252 nonn,look,base %O A338252 0,3 %A A338252 _Rémy Sigrist_, Oct 18 2020