OFFSET
0,7
COMMENTS
Limiting ratio a(n+1)/a(n) is -1.2207440846057594..., which is a root of z^4 + z - 1.
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (1,0,-1,2,-1).
FORMULA
Recurrence a(i)= a(i-1) - a(i-3) + 2 a(i-4) - a(i-5).
a(n) = (-1)^n*A175790(n).
MAPLE
N:= 100: # to get terms up to index N
for i from 0 to 4 do a[i]:= coeftayl(1/(1+x^3-x^4)/(1-x), x=0, i) end do:
for i from 5 to N do a[i]:= a[i-1] - a[i-3] + 2*a[i-4] - a[i-5] end do:
[seq(a[i], i=0..N)]; # Robert Israel, Feb 11 2013
MATHEMATICA
CoefficientList[ Series[1/(1 - x + x^3 - 2 x^4 + x^5), {x, 0, 50}], x] (* Or *)
LinearRecurrence[{1, 0, -1, 2, -1}, {1, 1, 1, 0, 1}, 51] (* Robert G. Wilson v, Feb 11 2013 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Roger L. Bagula, Dec 13 2010
EXTENSIONS
Recurrence, reference to A175790, and comment edited by Robert Israel, Feb 11 2013
STATUS
approved