OFFSET
1,2
COMMENTS
Row sums of triangle A133545.
LINKS
Index entries for linear recurrences with constant coefficients, signature (6,-13,12,-4).
FORMULA
G.f.: x*((1-2*x+x^2-x^3)/((x-1)^2*(2*x-1)^2)).
EXAMPLE
a(3) = 12 = sum of row 3 terms of triangle A133545: (6+5+1).
a(4) = 31 = (1,3,3,1) dot (1,3,5,6) = (1+9+15+6).
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Sep 15 2007
EXTENSIONS
Extended, edited and formula added by Olivier Gérard, Oct 12 2007
STATUS
approved