A124009 - OEIS

A124009

Number of permutations of n distinct letters (ABCD...) each of which appears thrice with one fixed point.

0, 0, 216, 49464, 23123880, 19180338840, 25791442770240, 52614269909090064, 154809621283047068016, 631429039396055199165840, 3457808596178310768284115720, 24763433580060911383347280813320

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..11.

EXAMPLE

0, "0", 0, 1

1, "0", 9, 0, 9, 0, 1

56, "216", 378, 435, 324, 189, 54", 27, 0, 1

13833, "49464", 84510, 90944, 69039, 38448, 16476, 5184, 1431, 216, 54, 0, 1

6699824, "23123880", 38358540, 40563765, 30573900, 17399178, 7723640, 2729295, 776520, 180100, 33372, 5355, 540, 90, 0, 1

etc...

MAPLE

p := (x, k)->k!^2*sum(x^j/((k-j)!^2*j!), j=0..k); R := (x, n, k)->p(x, k)^n; f := (t, n, k)->sum(coeff(R(x, n, k), x, j)*(t-1)^j*(n*k-j)!, j=0..n*k); for n from 0 to 6 do seq(coeff(f(t, n, 3), t, m)/3!^n, m=0..3*n); od;

CROSSREFS

Cf. A059058, A027468, A059073, A000459.

Sequence in context: A207314 A206697 A299994 * A134358 A167127 A269821

Adjacent sequences: A124006 A124007 A124008 * A124010 A124011 A124012

KEYWORD

nonn

AUTHOR

Zerinvary Lajos, Nov 01 2006

STATUS

approved