|
| |
|
|
A161702
|
|
(-n^3 + 9n^2 - 5n + 3)/3.
|
|
19
| |
|
|
1, 2, 7, 14, 21, 26, 27, 22, 9, -14, -49, -98, -163, -246, -349, -474, -623, -798, -1001, -1234, -1499, -1798, -2133, -2506, -2919, -3374, -3873, -4418, -5011, -5654, -6349, -7098, -7903, -8766, -9689, -10674, -11723, -12838, -14021, -15274
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| {a(k): 0 <= k < 4} = divisors of 14:
a(n) = A027750(A006218(13) + k + 1), 0 <= k < A000005(14).
|
|
|
LINKS
| R. Zumkeller, Enumerations of Divisors
Index to sequences with linear recurrences with constant coefficients, signature (4,-6,4,-1).
|
|
|
FORMULA
| a(n) = C(n,0) + C(n,1) + 4*C(n,2) - 2*C(n,3).
G.f.: (1-2*x+5*x^2-6*x^3)/(1-x)^4. [Colin Barker, Jan 08 2012]
|
|
|
EXAMPLE
| Differences of divisors of 14 to compute the coefficients of their interpolating polynomial, see formula:
1 ... 2 ... 7 ... 14
.. 1 ... 5 ... 7
..... 4 ... 2
....... -2.
|
|
|
PROG
| (MAGMA)[(-n^3 + 9*n^2 - 5*n + 3)/3: n in [0..50]]; [From Vincenzo Librandi, Dec 27 2010]
|
|
|
CROSSREFS
| Cf. A005408, A000124, A016813, A086514, A000125, A058331, A002522, A161701, A161703, A000127, A161704, A161706-A161708, A161710, A080856, A161711-A161713, A161715, A006261.
Sequence in context: A018349 A018363 A187142 * A087324 A008865 A018392
Adjacent sequences: A161699 A161700 A161701 * A161703 A161704 A161705
|
|
|
KEYWORD
| sign,easy
|
|
|
AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 17 2009
|
| |
|
|
