A179582 Number of permutations of 1..n+7 with the number moved left exceeding the number moved right by n or more

13831, 54048, 197961, 693696, 2357108, 7835766, 25638762, 82915640, 265808957, 846445116, 2681461839, 8459737368, 26600930930, 83414901730, 260966701576, 814822256976, 2539718326051, 7903832697048, 24563299810981, 76240724337360

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*(-13831 +222572*x -1606581*x^2 +6869968*x^3 -19343578*x^4 +37665466*x^5 -51764756*x^6 +50222224*x^7 -33717440*x^8 +14922528*x^9 -3919680*x^10 +463104*x^11) / ( (-1+3*x)^2*(2*x-1)^4*(x-1)^6 )

Crossrefs

Sequence in context: A250499 A013821 A013912 * A325886 A151642 A235004

Adjacent sequences: A179579 A179580 A179581 * A179583 A179584 A179585

Keyword

nonn

Author

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

Status

approved