|
|
A145923
|
|
Second bisection of A061041: a(n) = A061041(2n+1) = (2*n+1)*(2*n+9).
|
|
5
|
|
|
9, 33, 65, 105, 153, 209, 273, 345, 425, 513, 609, 713, 825, 945, 1073, 1209, 1353, 1505, 1665, 1833, 2009, 2193, 2385, 2585, 2793, 3009, 3233, 3465, 3705, 3953, 4209, 4473, 4745, 5025, 5313, 5609, 5913, 6225, 6545, 6873, 7209, 7553, 7905, 8265, 8633, 9009, 9393
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
|
|
FORMULA
|
a(n) = (2*n+1)*(2*n+9).
G.f.: (9 + 6*x - 7*x^2)/(1-x)^3 . - R. J. Mathar, Oct 23 2016
|
|
MATHEMATICA
|
LinearRecurrence[{3, -3, 1}, {9, 33, 65}, 100] (* Paolo Xausa, Dec 05 2023 *)
|
|
PROG
|
(Magma) [(2*n+5)^2-16: n in [0..60]]; // G. C. Greubel, Mar 23 2024
(SageMath) [(2*n+5)^2-16 for n in range(61)] # G. C. Greubel, Mar 23 2024
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy,less
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|