|
|
A024051
|
|
a(n) = 5^n - n^2.
|
|
2
|
|
|
1, 4, 21, 116, 609, 3100, 15589, 78076, 390561, 1953044, 9765525, 48828004, 244140481, 1220702956, 6103515429, 30517577900, 152587890369, 762939452836, 3814697265301, 19073486327764, 95367431640225
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
a(n) = 8*a(n-1) - 18*a(n-2) + 16*a(n-3) - 5*a(n-4).
|
|
MATHEMATICA
|
Table[5^n-n^2, {n, 0, 20}] (* or *) LinearRecurrence[{8, -18, 16, -5}, {1, 4, 21, 116}, 30] (* Harvey P. Dale, Nov 22 2012 *)
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|