OFFSET
1,1
COMMENTS
No recurrence is known.
LINKS
Lars Blomberg, Table of n, a(n) for n = 1..5000
Maran van Heesch, The multiplicative complexity of symmetric functions over a field with characteristic p, Thesis, 2014. See Table 3.
FORMULA
From Lars Blomberg, Dec 04 2016: (Start)
Empirically for 5000 terms:
Let k = n mod 4.
Formula:
k = 0: a(n) = -n*(n+1)*(n+2)/6.
k = 1: a(n) = -(n+3)*(n^2 + 3*n + 8)/6.
k = 2: a(n) = -(n-2)*(n+2)*(n+3)/6.
k = 3: a(n) = -(n+1)*(n+2)*(n+3)/6.
Recursion:
a(1..12) = (-8, 0, -20, -20, -64, -48, -120, -120, -232, -208, -364, -364).
a(n) = 3*a(n-4) - 3*a(n-8) + a(n-12) - 64, n > 12. (End)
Empirical g.f.: -4*x*(2 -2*x +3*x^2 +2*x^3 +2*x^4 +x^6) / ((1 -x)^4*(1 +x)^3*(1 +x^2)^2). - Colin Barker, Dec 04 2016
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Nov 19 2014
EXTENSIONS
More terms from Lars Blomberg, Dec 04 2016
STATUS
approved