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 A308881 Irregular array read by rows: row k (k>=1) contains k^2 numbers, formed by filling in a k X k square by upwards antidiagonals so entries in all rows, columns, diagonals, antidiagonals are distinct, and then reading that square across rows. 2
 0, 0, 2, 1, 3, 0, 2, 1, 1, 3, 4, 2, 0, 5, 0, 2, 1, 5, 1, 3, 4, 0, 2, 0, 5, 1, 3, 1, 2, 4, 0, 2, 1, 5, 3, 1, 3, 4, 0, 6, 2, 0, 5, 1, 7, 3, 1, 2, 4, 0, 4, 5, 0, 3, 1, 0, 2, 1, 5, 3, 4, 1, 3, 4, 0, 7, 2, 2, 0, 5, 1, 6, 9, 3, 1, 2, 4, 0, 5, 4, 6, 0, 3, 1, 7, 5, 7, 8, 6, 4, 10 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS The first row of the k X k square converges to A295563 as k increases. When filling in the k X k square, always choose the smallest possible number. Each k X k square is uniquely determined. LINKS 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. EXAMPLE The first eight squares are (here A=10, B=11, C=12): 0 -------- 02 13 -------- 021 134 205 -------- 0215 1340 2051 3124 -------- 02153 13406 20517 31240 45031 -------- 021534 134072 205169 312405 460317 57864A -------- 0215349 1340725 2051864 3124058 4603172 5786493 6432587 -------- 0215349A 13407258 20518643 31240786 4603152B 5786493C 64325879 756893A2 -------- CROSSREFS Cf. A295563, A308880. Sequence in context: A071467 A125073 A325310 * A281488 A071461 A091829 Adjacent sequences:  A308878 A308879 A308880 * A308882 A308883 A308884 KEYWORD nonn,tabf AUTHOR N. J. A. Sloane, Jun 29 2019 STATUS approved

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Last modified January 21 15:47 EST 2021. Contains 340352 sequences. (Running on oeis4.)