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A322255 Triangle T(n,k) giving the number of permutations of 1..n with no adjacent elements within k in value, for n >= 2, 1 <= k <= floor(n/2). 0
2, 6, 24, 2, 120, 14, 720, 90, 2, 5040, 646, 32, 40320, 5242, 368, 2, 362880, 47622, 3984, 72, 3628800, 479306, 44304, 1496, 2, 39916800, 5296790, 521606, 25384, 160, 479001600, 63779034, 6564318, 399848, 6056, 2, 6227020800, 831283558, 88422296, 6231544, 161136, 352 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Table of n, a(n) for n=2..43.

EXAMPLE

Irregular triangle starts:

n\k|       1       2      3     4  5

---+---------------------------------

2  |       2;

3  |       6;

4  |      24,      2;

5  |     120,     14;

6  |     720,     90,     2;

7  |    5040,    646,    32;

8  |   40320,   5242,   368,    2;

9  |  362880,  47622,  3984,   72;

10 | 3628800, 479306, 44304, 1496, 2;

CROSSREFS

Cf. A000142, A002464, A127697, A129534, A179957-A179967.

Sequence in context: A086554 A213324 A007672 * A084337 A323615 A204934

Adjacent sequences:  A322252 A322253 A322254 * A322256 A322257 A322258

KEYWORD

nonn,tabf

AUTHOR

Seiichi Manyama, Dec 01 2018

STATUS

approved

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Last modified November 11 22:31 EST 2019. Contains 329046 sequences. (Running on oeis4.)