OFFSET
0,2
COMMENTS
a(n)/a(n-1) tends to -4.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (-1,12).
FORMULA
G.f.: (1+5*x)/(1+x-12*x^2).
a(n) = Sum_{k, k=0..n} A112555(n,k)*3^k.
a(n) = (8*3^n-(-4)^n)/7. - Klaus Brockhaus, Sep 26 2009
E.g.f.: (8*exp(3*x) - exp(-4*x))/7. - G. C. Greubel, Oct 20 2018
MAPLE
MATHEMATICA
LinearRecurrence[{-1, 12}, {1, 4}, 30] (* Harvey P. Dale, Dec 26 2015 *)
PROG
(PARI) vector(40, n, n--; (8*3^n-(-4)^n)/7) \\ G. C. Greubel, Oct 20 2018
(Magma) [(8*3^n-(-4)^n)/7: n in [0..40]]; // G. C. Greubel, Oct 20 2018
(Python) for n in range(0, 30): print(int((8*3**n-(-4)**n)/7), end=', ') # Stefano Spezia, Oct 21 2018
(GAP) a:=[1, 4];; for n in [3..27] do a[n]:=12*a[n-2]-a[n-1]; od; a; # Muniru A Asiru, Oct 21 2018
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Philippe Deléham, Sep 20 2009
STATUS
approved