OFFSET
0,2
LINKS
Chai Wah Wu, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (7, -21, 35, -35, 21, -7, 1).
FORMULA
From Chai Wah Wu, Jun 04 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.: x*(461*x^5 - 2482*x^4 + 5376*x^3 - 5864*x^2 + 3228*x - 720)/(x - 1)^7. (End)
MATHEMATICA
LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {0, 720, 1812, 3428, 5768, 9090, 13721}, 40] (* Harvey P. Dale, Jul 20 2016 *)
PROG
(Python)
A090392_list, m = [], [1, 5, 18, 58, 177, 461, 0]
for _ in range(1001):
A090392_list.append(m[-1])
print(m[-1])
for i in range(6):
m[i+1] += m[i] # Chai Wah Wu, Jun 04 2016
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Philippe Deléham, Jan 31 2004
STATUS
approved