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

1,2

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.

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 *)

Crossrefs

Cf. A269526, A274315, A274316, A274317.

Sequence in context: A021219 A200127 A222069 * A256682 A303404 A002245

Adjacent sequences: A274315 A274316 A274317 * A274319 A274320 A274321

Keyword

nonn

Author

N. J. A. Sloane, Jun 29 2016

Extensions

More terms from Alois P. Heinz, Jun 29 2016

Status

approved