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 A187911 #11 Aug 08 2025 05:03:12 %S A187911 1,3,4,5,7,8,10,11,13,14,15,17,19,20,21,22,24,26,27,28,29,31,33,34,36, %T A187911 37,38,40,41,42,44,45,47,49,50,52,53,54,56,57,58,59,61,63,64,66,68,69, %U A187911 70,71,73,74,75,77,78,80,81,82,84,86,87,89,90,91,93,94,96,98,99,100,101,103,105,106,107,108,110,111,112,114,116,117,118,119 %N A187911 Rank transform of the sequence (1+floor(n*r)), where r=(-1+sqrt(5))/2; complement of A187912. %C A187911 See A187224. %t A187911 r=(-1+5^(1/2))/2; %t A187911 seqA = Table[1+Floor[r*n], {n, 1, 220}] (* A019446 *) %t A187911 seqB = Table[n, {n, 1, 220}]; (* A000027 *) %t A187911 jointRank[{seqA_, %t A187911 seqB_}] := {Flatten@Position[#1, {_, 1}], %t A187911 Flatten@Position[#1, {_, 2}]} &[ %t A187911 Sort@Flatten[{{#1, 1} & /@ seqA, {#1, 2} & /@ seqB}, 1]]; %t A187911 limseqU = %t A187911 FixedPoint[jointRank[{seqA, #1[[1]]}] &, %t A187911 jointRank[{seqA, seqB}]][[1]] (* A187911 *) %t A187911 Complement[Range[Length[seqA]], limseqU] (* A187912 *) %t A187911 (* _Peter J. C. Moses_, Mar 15 2011 *) %Y A187911 Cf. A187224, A187912. %K A187911 nonn %O A187911 1,2 %A A187911 _Clark Kimberling_, Mar 15 2011