OFFSET
0,2
REFERENCES
Nick Baxter, The Burnside di-lemma: combinatorics and puzzle symmetry, in Tribute to a Mathemagician, Peters, 2005, pp. 199-210.
LINKS
Chai Wah Wu, Table of n, a(n) for n = 0..1000
FORMULA
From Chai Wah Wu, Jun 05 2016: (Start)
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n > 6.
G.f.: 4*x*(1 + 3*x + 8*x^2 + 16*x^3 + 2*x^4)/(1 - x)^7. (End)
PROG
(Python)
A115286_list, m = [], [120, -300, 272, -96, 8, 0, 0]
for _ in range(1001):
A115286_list.append(m[-1])
for i in range(6):
m[i+1] += m[i] # Chai Wah Wu, Jun 05 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 11 2006
STATUS
approved