OFFSET
1,1
FORMULA
a(n+1)= (2*n^6 -6*n^5 +5*n^4 +60*n^3 -7*n^2 +306*n +720)/360 fits terms up to 5426026. [Frank Ellermann]
Empirical G.f.: -x*(x^6-7*x^5+25*x^4-32*x^3+26*x^2-11*x+2)/(x-1)^7. [Colin Barker, Sep 19 2012]
CROSSREFS
KEYWORD
nonn
AUTHOR
Svante Linusson (linusson(AT)math.kth.se)
STATUS
approved