OFFSET
1,2
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (2,-1,1,-1,-1,1,-1,2,-1).
FORMULA
From Stefano Spezia, Jun 20 2020: (Start)
G.f.: 4*x*(25 + 53*x + 83*x^2 + 87*x^3 + 67*x^4 + 35*x^5 + 10*x^6)/((1 - x)^4*(1 + 2*x + 3*x^2 + 3*x^3 + 2*x^4 + x^5)).
a(n) = 2*a(n-1) - a(n-2) + a(n-3) - a(n-4) - a(n-5) + a(n-6) - a(n-7) + 2*a(n-8) - a(n-9) for n > 9. (End)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jun 13 2020
EXTENSIONS
Terms a(6) and beyond from Giovanni Resta, Jun 20 2020
STATUS
approved