A179574 Number of permutations of 1..n+7 with the number moved left exceeding the number moved right by n

7736, 34659, 138022, 511412, 1807840, 6188910, 20713252, 68199003, 221845712, 715077749, 2288733954, 7285025030, 23085311544, 72888488904, 229435695984, 720341436677, 2256533814344, 7054866364855, 22017726215966, 68606973122472

Offset

1,1

Comments

Recurrence would also extend to an a(0) if the definition were made to exclude the identity permutation

Links

R. H. Hardin, Table of n, a(n) for n=1..32

Formula

Empirical: a(n)=20*a(n-1)-180*a(n-2)+964*a(n-3)-3422*a(n-4)+8484*a(n-5)-15068*a(n-6)+19324*a(n-7)-17769*a(n-8)+11432*a(n-9)-4888*a(n-10)+1248*a(n-11)-144*a(n-12) ; G.f.: -x*(-7736 +120061*x -837322*x^2 +3467912*x^3 -9484876*x^4 +17996064*x^5 -24175460*x^6 +22995433*x^7 -15176808*x^8 +6618712*x^9 -1716576*x^10 +200592*x^11) ) / ( (-1+3*x)^2*(2*x-1)^4*(x-1)^6 )

Crossrefs

Sequence in context: A092004 A278019 A146960 * A229419 A116239 A094400

Adjacent sequences: A179571 A179572 A179573 * A179575 A179576 A179577

Keyword

nonn

Author

R. H. Hardin, g.f. from R. J. Mathar in the Sequence Fans Mailing List, Jul 19 2010

Status

approved