OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..500
Index entries for linear recurrences with constant coefficients, signature (13,-48,40,-8).
FORMULA
From Andrew Howroyd, Oct 27 2020: (Start)
a(n) = 13*a(n-1) - 48*a(n-2) + 40*a(n-3) - 8*a(n-4) for n > 4.
G.f.: x*(1 + 2*x)/((1 - 7*x + 2*x^2)*(1 - 6*x + 4*x^2)).
(End)
EXAMPLE
From Andrew Howroyd, Oct 27 2020: (Start)
Some of the a(2) = 15 arrays are:
1 0 1 0 1 0 1 1 1 0
1 1 1 0 1 1 1 1 1 1
1 0 1 1 1 1 1 1 0 1
(End)
MATHEMATICA
LinearRecurrence[{13, -48, 40, -8}, {1, 15, 147, 1231}, 25] (* Paolo Xausa, Feb 08 2024 *)
PROG
(PARI) Vec((1 + 2*x)/((1 - 7*x + 2*x^2)*(1 - 6*x + 4*x^2)) + O(x^25)) \\ Andrew Howroyd, Oct 27 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Mar 22 2002
EXTENSIONS
Terms a(12) and beyond from Andrew Howroyd, Oct 27 2020
STATUS
approved