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A364817
Triangle read by rows: T(n,k) = number of permutations p of [n] such that max(|p(p(i)) - i|)=k (n>=1, 0<=k<=n-1).
1
1, 2, 0, 4, 0, 2, 10, 2, 6, 6, 26, 6, 22, 36, 30, 76, 24, 92, 144, 216, 168, 232, 80, 334, 640, 1150, 1524, 1080, 764, 312, 1328, 2984, 5516, 9712, 11784, 7920, 2620, 1152, 5234, 13296, 27668, 55750, 90240, 101400, 65520, 9496, 4616, 21780, 62124, 144564, 306272, 601756, 909312, 964080, 604800
OFFSET
1,2
FORMULA
T(n,n-1) = (2*n-5)*(n-2)! for n>3.
EXAMPLE
Triangle starts:
1;
2, 0;
4, 0, 2;
10, 2, 6, 6;
26, 6, 22, 36, 30;
76, 24, 92, 144, 216, 168;
232, 80, 334, 640, 1150, 1524, 1080;
764, 312, 1328, 2984, 5516, 9712, 11784, 7920;
2620, 1152, 5234, 13296, 27668, 55750, 90240, 101400, 65520;
CROSSREFS
Columns k=0..1 give: A000085, A364819.
Row sums give A000142.
Sequence in context: A335872 A239489 A259759 * A119607 A279968 A164297
KEYWORD
nonn,tabl
AUTHOR
Seiichi Manyama, Oct 21 2023
STATUS
approved