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A274318 Main diagonal of infinite Sudoku-type array A269526. 8
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 (list; graph; refs; listen; history; text; internal format)
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, arXiv:1907.09120, July 2019

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-Fran├žois 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

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Last modified January 19 15:37 EST 2020. Contains 331049 sequences. (Running on oeis4.)