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 A199134 #29 Dec 10 2016 17:00:34 %S A199134 4,5,10,11,13,15,20,21,26,27,29,31,34,38,40,42,43,49,50,54,56,58,59, %T A199134 64,67,69,71,75,77,78,80,85,86,90,91,95,99,101,102,104,108,111,113, %U A199134 116,117,120,123,128,129,132,133,136,141,143,144,146,151,152,154,156,160 %N A199134 Indices of Greedy Queens (see A065188) below main diagonal. %C A199134 The word "below" in the definition is somewhat ambiguous. More precisely, this is the list of n such that A065188(n) < n. - _N. J. A. Sloane_, Aug 18 2016 %C A199134 For Greedy Queens that do not attack along antidiagonals, the analogous sequence of indices is A026352. %H A199134 N. J. A. Sloane, <a href="/A199134/b199134.txt">Table of n, a(n) for n = 1..19098</a> %e A199134 Greedy Queens take positions (1,1) (2,3) (3,5) (4,2) (5,4) (6,9) ... and the 4th and 5th are below the main diagonal, so a(1)=4 and a(2)=5. %t A199134 <<DiscreteMath`Combinatorica`; %t A199134 base2=Table[{i,j},{i,0,256},{j,Floor[i/2],2i}]; %t A199134 base3=DeleteCases[base2,{k_,l_}/;Or[l<-2+Floor[k/GoldenRatio],l>2+Floor[k*GoldenRatio],And[l>3+Floor[k/GoldenRatio],l<Floor[k*GoldenRatio]]],2 ]; %t A199134 standardQueens=Backtrack[base3,(And[UnsameQ@@ First /@ #,UnsameQ@@ Last/@ #,UnsameQ@@ Subtract@@@ #,UnsameQ@@ Plus@@@ #])&,True&,One]; %t A199134 Position[Subtract@@@ standardQueens,_?Positive]//Flatten %Y A199134 Cf. A065188, A026352, A275893 (another version). %Y A199134 A275884 is the complementary sequence. %Y A199134 For runs see A275885, A275886. %K A199134 nonn %O A199134 1,1 %A A199134 _Wouter Meeussen_, Nov 04 2011