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 A334266 #9 Apr 25 2020 08:40:34 %S A334266 0,1,2,4,5,8,9,11,16,17,18,19,21,23,32,33,34,35,37,39,43,47,64,65,66, %T A334266 67,68,69,71,73,74,75,77,79,85,87,91,95,128,129,130,131,132,133,135, %U A334266 137,138,139,141,143,146,147,149,151,155,159,171,173,175,183,191 %N A334266 Numbers k such that the k-th composition in standard order is both a reversed Lyndon word and a co-Lyndon word. %C A334266 A Lyndon word is a finite sequence of positive integers that is lexicographically strictly less than all of its cyclic rotations. Co-Lyndon is defined similarly, except with strictly greater instead of strictly less. %C A334266 The k-th composition in standard order (graded reverse-lexicographic, A066099) is obtained by taking the set of positions of 1's in the reversed binary expansion of k, prepending 0, taking first differences, and reversing again. This gives a bijective correspondence between nonnegative integers and integer compositions. %F A334266 Intersection of A334265 and A326774. %e A334266 The sequence of all reversed Lyndon co-Lyndon words begins: %e A334266 0: () 37: (3,2,1) 91: (2,1,2,1,1) %e A334266 1: (1) 39: (3,1,1,1) 95: (2,1,1,1,1,1) %e A334266 2: (2) 43: (2,2,1,1) 128: (8) %e A334266 4: (3) 47: (2,1,1,1,1) 129: (7,1) %e A334266 5: (2,1) 64: (7) 130: (6,2) %e A334266 8: (4) 65: (6,1) 131: (6,1,1) %e A334266 9: (3,1) 66: (5,2) 132: (5,3) %e A334266 11: (2,1,1) 67: (5,1,1) 133: (5,2,1) %e A334266 16: (5) 68: (4,3) 135: (5,1,1,1) %e A334266 17: (4,1) 69: (4,2,1) 137: (4,3,1) %e A334266 18: (3,2) 71: (4,1,1,1) 138: (4,2,2) %e A334266 19: (3,1,1) 73: (3,3,1) 139: (4,2,1,1) %e A334266 21: (2,2,1) 74: (3,2,2) 141: (4,1,2,1) %e A334266 23: (2,1,1,1) 75: (3,2,1,1) 143: (4,1,1,1,1) %e A334266 32: (6) 77: (3,1,2,1) 146: (3,3,2) %e A334266 33: (5,1) 79: (3,1,1,1,1) 147: (3,3,1,1) %e A334266 34: (4,2) 85: (2,2,2,1) 149: (3,2,2,1) %e A334266 35: (4,1,1) 87: (2,2,1,1,1) 151: (3,2,1,1,1) %t A334266 stc[n_]:=Differences[Prepend[Join@@Position[Reverse[IntegerDigits[n,2]],1],0]]//Reverse; %t A334266 lynQ[q_]:=Length[q]==0||Array[Union[{q,RotateRight[q,#1]}]=={q,RotateRight[q,#1]}&,Length[q]-1,1,And]; %t A334266 colynQ[q_]:=Length[q]==0||Array[Union[{RotateRight[q,#],q}]=={RotateRight[q,#],q}&,Length[q]-1,1,And]; %t A334266 Select[Range[0,100],lynQ[Reverse[stc[#]]]&&colynQ[stc[#]]&] %Y A334266 The version for binary expansion is A334267. %Y A334266 Compositions of this type are counted by A334269. %Y A334266 Normal sequences of this type are counted by A334270. %Y A334266 Necklace compositions of this type are counted by A334271. %Y A334266 Binary Lyndon words are counted by A001037. %Y A334266 Lyndon compositions are counted by A059966. %Y A334266 All of the following pertain to compositions in standard order (A066099): %Y A334266 - Length is A000120. %Y A334266 - Necklaces are A065609. %Y A334266 - Sum is A070939. %Y A334266 - Reverse is A228351 (triangle). %Y A334266 - Strict compositions are A233564. %Y A334266 - Constant compositions are A272919. %Y A334266 - Lyndon words are A275692. %Y A334266 - Reversed Lyndon words are A334265. %Y A334266 - Co-Lyndon words are A326774. %Y A334266 - Reversed co-Lyndon words are A328596. %Y A334266 - Length of Lyndon factorization is A329312. %Y A334266 - Length of Lyndon factorization of reverse is A334297. %Y A334266 - Length of co-Lyndon factorization is A334029. %Y A334266 - Length of co-Lyndon factorization of reverse is A329313. %Y A334266 - Distinct rotations are counted by A333632. %Y A334266 - Co-Lyndon factorizations are counted by A333765. %Y A334266 - Lyndon factorizations are counted by A333940. %Y A334266 Cf. A000740, A008965, A065609, A329324, A333764, A333943, A334272, A334297. %K A334266 nonn %O A334266 1,3 %A A334266 _Gus Wiseman_, Apr 22 2020