A390782 Number of n X n grids with 4 non-attacking kings on each row.

1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 70, 63537916, 1379464330296028, 6533334499649986797318, 31148359575015040661611022930, 118890295619850832499622492028217548, 400210683237685599476459218275550085957794, 1235402690137298116747522430328764793204234898404

Offset

0,16

Links

Hamidreza Maleki Tirabadi, Table of n, a(n) for n = 0..30

Formula

See A390419.

Example

a(15) = 70. One of the 70 solutions is:
  Row 1: [0, 2, 4, 6]     -> * ° * ° * ° * ° ° ° ° ° ° ° °
  Row 2: [8, 10, 12, 14]  -> ° ° ° ° ° ° ° ° * ° * ° * ° *
  Row 3: [0, 2, 4, 6]     -> * ° * ° * ° * ° ° ° ° ° ° ° °
  Row 4: [8, 10, 12, 14]  -> ° ° ° ° ° ° ° ° * ° * ° * ° *
  Row 5: [0, 2, 4, 6]     -> * ° * ° * ° * ° ° ° ° ° ° ° °
  Row 6: [8, 10, 12, 14]  -> ° ° ° ° ° ° ° ° * ° * ° * ° *
  Row 7: [0, 2, 4, 6]     -> * ° * ° * ° * ° ° ° ° ° ° ° °
  Row 8: [8, 10, 12, 14]  -> ° ° ° ° ° ° ° ° * ° * ° * ° *
  Row 9: [0, 2, 4, 6]     -> * ° * ° * ° * ° ° ° ° ° ° ° °
  Row 10: [8, 10, 12, 14] -> ° ° ° ° ° ° ° ° * ° * ° * ° *
  Row 11: [0, 2, 4, 6]    -> * ° * ° * ° * ° ° ° ° ° ° ° °
  Row 12: [8, 10, 12, 14] -> ° ° ° ° ° ° ° ° * ° * ° * ° *
  Row 13: [0, 2, 4, 6]    -> * ° * ° * ° * ° ° ° ° ° ° ° °
  Row 14: [8, 10, 12, 14] -> ° ° ° ° ° ° ° ° * ° * ° * ° *
  Row 15: [0, 2, 4, 6]    -> * ° * ° * ° * ° ° ° ° ° ° ° °

Crossrefs

Column k=4 of A390419.

Cf. A387098.

Sequence in context: A222746 A066789 A103165 * A116276 A056666 A172680

Adjacent sequences: A390779 A390780 A390781 * A390783 A390784 A390785

Keyword

nonn

Author

Hamidreza Maleki Tirabadi, Nov 19 2025

Status

approved