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 A201219 #20 Dec 03 2021 15:34:44 %S A201219 0,1,2,1,2,2,2,1,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2, %T A201219 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2, %U A201219 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2 %N A201219 a(1) = 0; for n>1, a(n) = 1 if n is a power of 2, otherwise a(n) = 2. %C A201219 This solves the Emissary puzzle. %H A201219 Antti Karttunen, <a href="/A201219/b201219.txt">Table of n, a(n) for n = 1..16384</a> %H A201219 <a href="http://www.msri.org/attachments/media/news/emissary/EmissaryFall2011.pdf">Puzzles Column</a>, Emissary, Fall 2011, page 9, puzzle 6. %F A201219 a(1) = 0, for n > 1, a(n) = 2 - A209229(n). - _Antti Karttunen_, Nov 19 2017 %t A201219 Join[{0},Table[If[IntegerQ[Log2[n]],1,2],{n,2,200}]] (* _Harvey P. Dale_, Dec 03 2021 *) %Y A201219 Cf. A043529, A209229. %K A201219 nonn %O A201219 1,3 %A A201219 _N. J. A. Sloane_, Nov 28 2011