|
|
A153976
|
|
a(n) = n^3 + (n+2)^3.
|
|
5
|
|
|
8, 28, 72, 152, 280, 468, 728, 1072, 1512, 2060, 2728, 3528, 4472, 5572, 6840, 8288, 9928, 11772, 13832, 16120, 18648, 21428, 24472, 27792, 31400, 35308, 39528, 44072, 48952, 54180, 59768, 65728, 72072, 78812, 85960, 93528, 101528, 109972, 118872, 128240
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
|
|
FORMULA
|
For n>3, a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). - Harvey P. Dale, Aug 02 2011
G.f.: 4*( 2-x+2*x^2 ) / (x-1)^4 . - R. J. Mathar, Apr 11 2016
|
|
MATHEMATICA
|
f[n_]:=n^3; lst={}; Do[AppendTo[lst, (f[n]+f[n+2])], {n, 0, 6!}]; lst
Array[#^3+(#+2)^3&, 40, 0] (* or *) LinearRecurrence[{4, -6, 4, -1}, {8, 28, 72, 152}, 40] (* Harvey P. Dale, Aug 02 2011 *)
|
|
PROG
|
(Python)
def a(n): return n**3 + (n+2)**3
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|