OFFSET
0,1
COMMENTS
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (6, -8).
FORMULA
a(n) = 3*4^(n+7)-12576771*2^(n-5) for n > 8.
G.f.: (221+1428*x-2300*x^2+24993*x^3+223335*x^4+2415633*x^5 +20941524*x^6-28157325*x^7+2146570770*x^8-3999357024*x^9-390079584*x^10) / ((1-2*x)*(1-4*x)).
G.f. for the sequence starting at a(9): 48*x^9*(264243199-520101884*x) / ((1-2*x)*(1-4*x)).
MATHEMATICA
CoefficientList[Series[(221 + 1428 x - 2300 x^2 + 24993 x^3 + 223335 x^4 + 2415633 x^5 + 20941524 x^6 - 28157325 x^7 + 2146570770 x^8 - 3999357024 x^9 - 390079584 x^10)/((1 - 2 x) (1 - 4 x)), {x, 0, 40}], x] (* Vincenzo Librandi, Sep 24 2013 *)
LinearRecurrence[{6, -8}, {221, 2754, 12456, 77697, 589869, 5333271, 48222198, 218509695, 3071851356, 12683673552, 51137150880}, 20] (* Harvey P. Dale, Nov 02 2020 *)
PROG
(PARI) {m=18; v=concat([221, 2754, 12456, 77697, 589869, 5333271, 48222198, 218509695, 3071851356, 12683673552, 51137150880], vector(m-11)); for(n=12, m, v[n]=6*v[n-1]-8*v[n-2]); v}
(Magma) [221, 2754, 12456, 77697, 589869, 5333271, 48222198, 218509695, 3071851356] cat [3*4^(n+7)-12576771*2^(n-5): n in [9..25]]; // Vincenzo Librandi, Sep 24 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Klaus Brockhaus, May 07 2010
STATUS
approved