A179573 Number of permutations of 1..n+6 with the number moved left exceeding the number moved right by n

1289, 4859, 16615, 53830, 168994, 520598, 1585390, 4794375, 14437999, 43373253, 130121945, 390106124, 1169206896, 3504084520, 10502294920, 31480673141, 94375961733, 282966406751, 848513346011, 2544634069346, 7631805056014

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..45

Formula

Empirical: a(n)=14*a(n-1)-85*a(n-2)+294*a(n-3)-639*a(n-4)+906*a(n-5)-839*a(n-6)+490*a(n-7)-164*a(n-8)+24*a(n-9) ; G.f.: -x*(1289-13187*x+58154*x^2-144731*x^3+222774*x^4-217511*x^5+131690*x^6-45220*x^7+6744*x^8) / ( (-1+3*x)*(2*x-1)^3*(x-1)^5 ).

Empirical: a(n) = 3^(n+6) +(n+6)*(n^3-12*n^2-133*n-192)/24 +(n^2-n-50)*2^(n+3). - R. J. Mathar, May 26 2016

Crossrefs

Sequence in context: A140914 A239436 A239939 * A264243 A020401 A106816

Adjacent sequences: A179570 A179571 A179572 * A179574 A179575 A179576

Keyword

nonn

Author

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

Status

approved