OFFSET
1,1
COMMENTS
The numbers can be generated from row sums from coefficients of the polynomials Sum_{i=1..n} ((n+1)^2 - 1 + (n+1-i)*z^n)*z^(i-1)/i.
The coefficients written as an array of 2n numbers in row n for the first 5 polynomials are
3 1 <- 3+z
8 4 2 1/2 <- 8+4z+2z^2+z^3/2
15 15/2 5 3 1 1/3
24 12 8 6 4 3/2 2/3 1/4
35 35/2 35/3 35/4 7 5 2 1 1/2 1/5
These rows multiplied by n! are
3 1
16 8 4 1
90 45 30 18 6 2
576 288 192 144 96 36 16 6
4200 2100 1400 1050 840 600 240 120 60 24
where the first column is A129326. The latter row sums define a(n), which are n! times the polynomials evaluated at z=1.
CROSSREFS
KEYWORD
nonn,less
AUTHOR
Paul Curtz, May 30 2007
EXTENSIONS
Edited and corrected by R. J. Mathar, Jul 27 2008
STATUS
approved