OFFSET
0,1
COMMENTS
Column six is associated with the following partitions: 66, 552, 443, 4422, 3332, 33222 and 222222.
LINKS
Index entries for linear recurrences with constant coefficients, signature (8,-28,56,-70,56,-28,8,-1). [From R. J. Mathar, Jun 26 2010]
FORMULA
a(n) = A107601(10+n,5+n) = n*(1384+4683*n^2+2142*n+2*n^6+651*n^4+63*n^5+2835*n^3)/1680. a(n)= +8*a(n-1) -28*a(n-2) +56*a(n-3) -70*a(n-4) +56*a(n-5) -28*a(n-6) +8*a(n-7) -a(n-8). G.f.: x*(7+15*x-22*x^2+11*x^4-6*x^5+x^6)/(x-1)^8. [From R. J. Mathar, Jun 26 2010]
EXAMPLE
a(1) = 7 because there are 3 permutations of 443 and 4 permutations of 3332.
a(2) = 71 because there are 1 + 3 + 18 + 6 + 32 + 10 + 1 permutations of the associated partitions.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alford Arnold, May 27 2005
EXTENSIONS
Extended beyond a(5) by R. J. Mathar, Jun 26 2010
STATUS
approved