OFFSET
0,2
LINKS
Chai Wah Wu, Table of n, a(n) for n = 0..1000
FORMULA
From Chai Wah Wu, Jun 04 2016: (Start)
a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n > 7.
G.f.: x*(3447*x^6 - 21824*x^5 + 57742*x^4 - 81760*x^3 + 65388*x^2 - 28032*x + 5040)/(x - 1)^8. (End)
PROG
(Python)
A090393_list, m = [], [1, 6, 25, 92, 327, 1142, 3447, 0]
for _ in range(1001):
A090393_list.append(m[-1])
print(m[-1])
for i in range(7):
m[i+1] += m[i] # Chai Wah Wu, Jun 04 2016
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Philippe Deléham, Jan 31 2004
STATUS
approved