OFFSET
2,1
LINKS
Andrew Howroyd, Table of n, a(n) for n = 2..200
Index entries for linear recurrences with constant coefficients, signature (130,-5260,68760,-362880,677376).
FORMULA
a(n) = n*(23^2*56^(n-2) + 21*6^(n-2) - 75*n*6^(n-2))/10. - Andrew Howroyd, May 10 2020
From Colin Barker, Jul 16 2020: (Start)
G.f.: 40*x^2*(2 + 3*x)*(1 - 25*x - 303*x^2 + 252*x^3) / ((1 - 6*x)^3*(1 - 56*x)^2).
a(n) = 130*a(n-1) - 5260*a(n-2) + 68760*a(n-3) - 362880*a(n-4) + 677376*a(n-5) for n>6.
(End)
PROG
(PARI) a(n) = {n*(23^2*56^(n-2) + 21*6^(n-2) - 75*n*6^(n-2))/10} \\ Andrew Howroyd, May 10 2020
(PARI) Vec(40*x^2*(2 + 3*x)*(1 - 25*x - 303*x^2 + 252*x^3) / ((1 - 6*x)^3*(1 - 56*x)^2) + O(x^18)) \\ Colin Barker, Jul 16 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Apr 20 2009
EXTENSIONS
Terms a(7) and beyond from Andrew Howroyd, May 09 2020
STATUS
approved