|
|
A129441
|
|
Expansion of g.f. (1-x^2-x^3)/((1+x+x^2)*(1-2*x-x^2-x^3+x^4)).
|
|
3
|
|
|
1, 1, 2, 7, 16, 39, 100, 248, 618, 1546, 3858, 9631, 24049, 60041, 149903, 374266, 934427, 2332981, 5824753, 14542648, 36308602, 90651625, 226329747, 565077072, 1410826915, 3522409024, 8794392287, 21956943442, 54819861280, 136868649264
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
LINKS
|
|
|
FORMULA
|
a(n) = a(n-1) +2*a(n-2) +4*a(n-3) +a(n-4) -a(n-6).
|
|
MATHEMATICA
|
LinearRecurrence[{1, 2, 4, 1, 0, -1}, {1, 1, 2, 7, 16, 39}, 40] (* Harvey P. Dale, Nov 26 2015 *)
|
|
PROG
|
(Magma) R<x>:=PowerSeriesRing(Integers(), 40); Coefficients(R!( (1-x^2-x^3)/((1+x+x^2)*(1-2*x-x^2-x^3+x^4)) )); // G. C. Greubel, Feb 06 2024
(SageMath)
P.<x> = PowerSeriesRing(ZZ, prec)
return P( (1-x^2-x^3)/((1+x+x^2)*(1-2*x-x^2-x^3+x^4)) ).list()
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,less
|
|
AUTHOR
|
|
|
EXTENSIONS
|
Definition simplified - the Assoc. Eds of the OEIS, Mar 28 2010
|
|
STATUS
|
approved
|
|
|
|