A274318 Main diagonal of infinite Sudoku-type array A269526.

1, 4, 6, 5, 2, 10, 8, 3, 7, 9, 16, 26, 29, 22, 20, 23, 28, 38, 12, 32, 46, 13, 14, 11, 15, 56, 35, 58, 47, 48, 24, 18, 21, 69, 17, 52, 41, 19, 82, 83, 70, 25, 30, 62, 93, 27, 65, 106, 78, 102, 37, 110, 112, 76, 116, 119, 92, 31, 34, 49, 39, 101, 33, 36, 138

Offset: 1

Author

N. J. A. Sloane, Jun 29 2016

Keywords

• nonn

Comments

Conjectured to be a permutation of the natural numbers.

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..1000
• F. Michel Dekking, Jeffrey Shallit, and N. J. A. Sloane, Queens in exile: non-attacking queens on infinite chess boards, Electronic J. Combin., 27:1 (2020), #P1.52.

Crossrefs

Cf. A269526, A274315, A274316, A274317.

Programs

Mathematica

A[n_, k_] := A[n, k] = If[n == 1 && k == 1, 1, s = {Table[A[i, k], {i, 1, n - 1}], Table[A[n, j], {j, 1, k - 1}], Table[A[n - t, k - t], {t, 1, Min[n, k] - 1}], Table[A[n + j, k - j], {j, 1, k - 1}]} // Flatten; For[m = 1, True, m++, If[FreeQ[s, m], Return[m]]]];
a[n_] := A[n, n];
Array[a, 65] (* Jean-François Alcover, Jun 10 2017, after Alois P. Heinz *)

Extensions

More terms from Alois P. Heinz, Jun 29 2016