A396655 Consider the 0-indexed spiral on a hexagonal grid, as in A395365. Three players, Red, Green and Blue, take turns and place knights at the smallest unoccupied cell not attacked by an opposing knight. Sequence lists cells occupied by Blue knights.

2, 5, 40, 43, 45, 55, 57, 62, 66, 68, 74, 89, 90, 101, 102, 103, 119, 120, 121, 122, 132, 180, 184, 205, 208, 213, 214, 221, 230, 232, 235, 236, 258, 259, 263, 264, 273, 278, 285, 290, 304, 316, 320, 324, 326, 329, 346, 349, 351, 352, 353, 380, 383, 384, 386

Offset

1,1

Comments

See A396653 for comments and images.

Links

Table of n, a(n) for n=1..55.

Crossrefs

Cf. A395365, A396653, A396654.

Sequence in context: A307141 A109003 A120031 * A110066 A155176 A127974

Adjacent sequences: A396652 A396653 A396654 * A396656 A396657 A396658

Keyword

nonn

Author

Nick J. Nauta, Jun 01 2026

Status

approved