|
|
A168559
|
|
a(n) = n^2 + a(n-1), with a(1)=0.
|
|
5
|
|
|
0, 4, 13, 29, 54, 90, 139, 203, 284, 384, 505, 649, 818, 1014, 1239, 1495, 1784, 2108, 2469, 2869, 3310, 3794, 4323, 4899, 5524, 6200, 6929, 7713, 8554, 9454, 10415, 11439, 12528, 13684, 14909, 16205, 17574, 19018, 20539, 22139, 23820, 25584
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
Sum of the first n perfect squares (A000330), minus 1.
|
|
LINKS
|
|
|
FORMULA
|
a(1)=0, a(2)=4, a(3)=13, a(4)=29, a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). - Harvey P. Dale, Dec 07 2013
|
|
MATHEMATICA
|
RecurrenceTable[{a[1]==0, a[n]==n^2+a[n-1]}, a, {n, 50}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {0, 4, 13, 29}, 50] (* Harvey P. Dale, Dec 07 2013 *)
|
|
PROG
|
(Haskell)
a168559 n = a168559_list !! (n-1)
a168559_list = scanl (+) 0 $ drop 2 a000290_list
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|