|
| |
|
|
A239449
|
|
7*n^2 - 5*n + 1.
|
|
3
|
|
|
|
1, 3, 19, 49, 93, 151, 223, 309, 409, 523, 651, 793, 949, 1119, 1303, 1501, 1713, 1939, 2179, 2433, 2701, 2983, 3279, 3589, 3913, 4251, 4603, 4969, 5349, 5743, 6151, 6573, 7009, 7459, 7923, 8401, 8893, 9399, 9919, 10453, 11001, 11563, 12139, 12729, 13333
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,2
|
|
|
COMMENTS
|
a(n) = A239426(n) / A003215(n-1).
|
|
|
LINKS
|
Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
|
|
|
FORMULA
|
G.f.: ( -1-13*x^2 ) / (x-1)^3 . - R. J. Mathar, Mar 31 2014
|
|
|
MATHEMATICA
|
CoefficientList[Series[(1 + 13 x^2)/(1 - x)^3, {x, 0, 50}], x] (* Vincenzo Librandi, Apr 02 2014 *)
|
|
|
PROG
|
(Haskell)
a239449 n = (7 * n - 5) * n + 1
(MAGMA) [7*n^2-5*n+1: n in [0..50]]; // Vincenzo Librandi, Apr 02 2014
(PARI) a(n)=7*n^2-5*n+1 \\ Charles R Greathouse IV, Jun 17 2017
|
|
|
CROSSREFS
|
Sequence in context: A023280 A054697 A214883 * A112627 A222185 A265774
Adjacent sequences: A239446 A239447 A239448 * A239450 A239451 A239452
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
Reinhard Zumkeller, Mar 19 2014
|
|
|
STATUS
|
approved
|
| |
|
|
