|
|
A017558
|
|
a(n) = (12*n + 3)^2.
|
|
1
|
|
|
9, 225, 729, 1521, 2601, 3969, 5625, 7569, 9801, 12321, 15129, 18225, 21609, 25281, 29241, 33489, 38025, 42849, 47961, 53361, 59049, 65025, 71289, 77841, 84681, 91809, 99225, 106929, 114921, 123201
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
|
|
FORMULA
|
G.f.: 9*(1 + 22*x + 9*x^2)/(1-x)^3.
|
|
MATHEMATICA
|
(12*Range[0, 30]+3)^2 (* or *) LinearRecurrence[{3, -3, 1}, {9, 225, 729}, 30] (* Harvey P. Dale, Aug 04 2015 *)
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|