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 A335061 #18 May 25 2020 23:20:03 %S A335061 0,1,0,0,2,0,6,11,13,0,14,0,30,39,57,0,8,54,62,83,91,101,109,0,126, %T A335061 151,233,0,40,92,116,138,162,214,254,0,72,140,196,314,370,438,510,543, %U A335061 599,659,731,805,877,937,993,0,168,854,1022,1379,1483,1589,1693 %N A335061 Irregular table read by rows; n-th row corresponds to numbers in the range 0..2^n-1 whose binary expansion (possibly left-padded with 0's up to n binary digits) generates rotationally symmetric XOR-triangles. %C A335061 The n-th row has A060547(n) terms. %C A335061 Every positive term of A334556, say m, appears in row A070939(m). %H A335061 Michael De Vlieger, <a href="/A335061/b335061.txt">Table of n, a(n) for n = 1..1275</a> (rows 1 <= n <= 24, flattened) %H A335061 A. Barbé, <a href="http://dx.doi.org/10.1016/S0166-218X(00)00211-0">Symmetric patterns in the cellular automaton that generates Pascal's triangle modulo 2</a>, Discr. Appl. Math. 105(2000), 1-38. %H A335061 Michael De Vlieger, <a href="/A335061/a335061_1.png">Diagram montage</a> showing 486 XOR-triangles T(n,k)>0 for 3 <= n <= 20. %H A335061 Michael De Vlieger, Large 50X25 <a href="/A335061/a335061_2.png">Diagram montage</a> showing 1250 XOR-triangles T(n,k)>0 for 3 <= n <= 24. %H A335061 Rémy Sigrist, <a href="/A335061/a335061.png">Triangles illustrating the initial terms</a> %H A335061 Rémy Sigrist, <a href="/A335061/a335061.gp.txt">PARI program for A335061</a> %H A335061 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %H A335061 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a> %H A335061 <a href="/index/X#XOR-triangles">Index entries for sequences related to XOR-triangles</a> %e A335061 The first rows are: %e A335061 0, 1 %e A335061 0 %e A335061 0, 2 %e A335061 0, 6, 11, 13 %e A335061 0, 14 %e A335061 0, 30, 39, 57 %e A335061 0, 8, 54, 62, 83, 91, 101, 109 %e A335061 The XOR-triangles corresponding to the 8 terms of row 7 are (with dots instead of 0's for clarity): %e A335061 T(7,1) = 0: T(7,2) = 8: T(7,3) = 54: T(7,4) = 62, %e A335061 . . . . . . . . . . 1 . . . . 1 1 . 1 1 . . 1 1 1 1 1 . %e A335061 . . . . . . . . 1 1 . . 1 . 1 1 . 1 1 . . . . 1 %e A335061 . . . . . . 1 . 1 . 1 1 . 1 1 1 . . . 1 %e A335061 . . . . 1 1 1 1 . 1 1 . 1 . . 1 %e A335061 . . . . . . 1 . 1 1 . 1 %e A335061 . . . . 1 1 1 1 %e A335061 . . . . %e A335061 T(7,5) = 83: T(7,6) = 91: T(7,7) = 101: T(7,8) = 109: %e A335061 1 . 1 . . 1 1 1 . 1 1 . 1 1 1 1 . . 1 . 1 1 1 . 1 1 . 1 %e A335061 1 1 1 . 1 . 1 1 . 1 1 . . 1 . 1 1 1 . 1 1 . 1 1 %e A335061 . . 1 1 1 . 1 1 . 1 1 1 1 . . 1 . 1 1 . %e A335061 . 1 . . 1 . 1 1 . . 1 . 1 1 . 1 %e A335061 1 1 . 1 1 . . 1 1 . 1 1 %e A335061 . 1 . 1 1 . 1 . %e A335061 1 1 1 1 %t A335061 Table[Select[Range[0, 2^n - 1], Block[{k = #, w}, (Reverse /@ Transpose[#] /. -1 -> Nothing) == w &@ MapIndexed[PadRight[#, n, -1] &, Set[w, NestList[Map[BitXor @@ # &, Partition[#, 2, 1]] &, PadLeft[IntegerDigits[k, 2], n], n - 1]]]] &], {n, 12}] // Flatten (* _Michael De Vlieger_, May 24 2020 *) %o A335061 (PARI) See Links section. %Y A335061 Cf. A060547 (row length), A070939, A334556. %K A335061 nonn,base,tabf %O A335061 1,5 %A A335061 _Rémy Sigrist_, May 21 2020