A396123 Consider the square spiral with its cells numbered starting at 0. Five players take turns and place knights at the smallest unoccupied cell not attacked by an existing knight of a different player. Sequence lists squares occupied by the second player.

1, 4, 22, 28, 43, 47, 55, 70, 85, 92, 115, 127, 142, 144, 150, 157, 160, 178, 194, 200, 204, 208, 217, 246, 250, 255, 258, 277, 297, 299, 318, 320, 324, 336, 346, 351, 376, 390, 394, 398, 404, 408, 427, 445, 468, 472, 476, 483, 484, 486, 494, 511, 539, 545

Offset

1,2

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Rémy Sigrist, PARI program

Prog

(PARI) \\ See Links section.

Crossrefs

Cf. A392177, A396122, A396124, A396125, A396126, A396127, A396128.

Sequence in context: A204341 A036920 A036921 * A396130 A083510 A277586

Adjacent sequences: A396120 A396121 A396122 * A396124 A396125 A396126

Keyword

nonn

Author

Rémy Sigrist, May 22 2026

Status

approved