OFFSET
0,3
REFERENCES
M. Kosuda and M. Oura, Centralizer algebras of the group associated to Z_4-codes, Discrete Math., 340 (2017), 2437-2446.
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
M. Kosuda and M. Oura, Centralizer algebras of the group associated to Z_4-codes, arXiv:1608.08731 [math.RT], 2016-2017.
Index entries for linear recurrences with constant coefficients, signature (15,-59,45).
FORMULA
For n>0, a(n) = (57+6*5^n+9^n)/96.
From Colin Barker, Sep 25 2017: (Start)
G.f.: (1 - 14*x + 47*x^2 - 15*x^3) / ((1 - x)*(1 - 5*x)*(1 - 9*x)).
a(n) = 15*a(n-1) - 59*a(n-2) + 45*a(n-3) for n>3.
(End)
PROG
(PARI) a(n) = if (n==0, 1, (57+6*5^n+9^n)/96); \\ Michel Marcus, Sep 25 2017
(PARI) Vec((1 - 14*x + 47*x^2 - 15*x^3) / ((1 - x)*(1 - 5*x)*(1 - 9*x)) + O(x^30)) \\ Colin Barker, Sep 25 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Sep 24 2017
EXTENSIONS
More terms from Michel Marcus, Sep 25 2017
STATUS
approved