OFFSET
0,3
LINKS
Stefano Spezia, Table of n, a(n) for n = 0..990
Index entries for linear recurrences with constant coefficients, signature (33,-393,1991,-3930,3300,-1000).
FORMULA
O.g.f.: x*(1 - 30*x^2 + 110*x^3)/((1 - x)^3*(1 - 10*x)^3).
E.g.f.: exp(x)*x*(20*exp(9*x)*(1 + 5*x) - 2 - x)/18.
a(n) = 33*a(n-1) - 393*a(n-2) + 1991*a(n-3) - 3930*a(n-4) + 3300*a(n-5) - 1000*a(n-6) for n > 5.
MATHEMATICA
Table[n(1+n)(10^n-1)/18, {n, 0, 20}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Stefano Spezia, Sep 14 2023
STATUS
approved