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A283117
Number of nonequivalent ways (mod D_3) to place rooks on an n X n X n triangular grid so that no two of them are on the same row, column or diagonal.
3
2, 2, 4, 8, 19, 51, 169, 592, 2281, 9268, 39521, 175875, 813780, 3903533, 19367571, 99208196, 523695465, 2844708347, 15877906262, 90955375095, 534101204061
OFFSET
1,1
FORMULA
a(n) = Sum_{k=0..A004396(n)} A283113(n,k).
a(n) = (A289709(n) + 2*A326611(n) + 3*2^ceiling(n/2))/6. - Andrew Howroyd, Sep 12 2019
CROSSREFS
Row sums of A283113.
Sequence in context: A168055 A005702 A095335 * A334325 A100396 A056630
KEYWORD
nonn,more
AUTHOR
R. J. Mathar, Jul 07 2017
EXTENSIONS
Name changed by Andrew Howroyd, Sep 12 2019
STATUS
approved