OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..300
Justin Meiners, Computing the Rank of Braids, Master's Thesis, Brigham Young University (2021) 8947.
Index entries for linear recurrences with constant coefficients, signature (129,-3000,10000).
FORMULA
a(n) = (25*4^n+16*25^n +100^n)/60.
a(n) = 129*a(n-1)-3000*a(n-2)+10000*a(3). - Colin Barker, May 28 2015
G.f.: -10*x*(700*x^2-95*x+1) / ((4*x-1)*(25*x-1)*(100*x-1)). - Colin Barker, May 28 2015
MATHEMATICA
Rest@ CoefficientList[Series[-10 x (700 x^2 - 95 x + 1)/((4 x - 1)*(25 x - 1)*(100 x - 1)), {x, 0, 15}], x] (* Michael De Vlieger, Jul 06 2021 *)
PROG
(Magma) [(25*4^n+16*25^n +100^n)/60: n in [1..15]]; // Vincenzo Librandi, Jun 30 2011
(PARI) Vec(-10*x*(700*x^2-95*x+1) / ((4*x-1)*(25*x-1)*(100*x-1)) + O(x^100)) \\ Colin Barker, May 28 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paolo Dominici (pl.dm(AT)libero.it)
STATUS
approved