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 A333780 #10 Apr 07 2020 12:20:01 %S A333780 0,1,4,3,2,11,12,13,10,9,8,5,6,7,34,33,32,35,36,37,40,39,38,29,30,31, %T A333780 28,27,26,23,24,25,16,15,14,17,18,19,22,21,20,101,102,103,100,99,98, %U A333780 95,96,97,106,105,104,107,108,109,112,111,110,119,120,121,118 %N A333780 a(n) = g(-n) - g(n), where g corresponds to the inverse of A333773. %C A333780 This sequence appears to be a self-inverse permutation of the nonnegative integers. %H A333780 Rémy Sigrist, <a href="/A333780/b333780.txt">Table of n, a(n) for n = 0..6561</a> %H A333780 Rémy Sigrist, <a href="/A333780/a333780.gp.txt">PARI program for A333780</a> %e A333780 For n = 2: %e A333780 - A333773(4) = 2, g(2) = 4, %e A333780 - A333773(8) = -2, g(-2) = 8, %e A333780 - so a(2) = 8 - 4 = 4. %o A333780 (PARI) See Links section. %Y A333780 Cf. A333773. %K A333780 nonn,base %O A333780 0,3 %A A333780 _Rémy Sigrist_, Apr 05 2020