|
|
A024078
|
|
a(n) = 7^n - n^3.
|
|
2
|
|
|
1, 6, 41, 316, 2337, 16682, 117433, 823200, 5764289, 40352878, 282474249, 1977325412, 13841285473, 96889008210, 678223070105, 4747561506568, 33232930565505, 232630513982294, 1628413597904617, 11398895185366284, 79792266297604001, 558545864083274746
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (1 + x)*(1 - 6*x + 15*x^2 + 8*x^3) / ((1 - x)^4*(1 - 7*x)).
a(n) = 11*a(n-1) - 34*a(n-2) + 46*a(n-3) - 29*a(n-4) + 7*a(n-5) for n>4.
(End)
|
|
PROG
|
(PARI) Vec((1 + x)*(1 - 6*x + 15*x^2 + 8*x^3) / ((1 - x)^4*(1 - 7*x)) + O(x^30)) \\ Colin Barker, Oct 05 2018
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|