|
| |
|
|
A124395
|
|
Expansion of (1-2x)/(1-2x+2x^3).
|
|
3
| |
|
|
1, 0, 0, -2, -4, -8, -12, -16, -16, -8, 16, 64, 144, 256, 384, 480, 448, 128, -704, -2304, -4864, -8320, -12032, -14336, -12032, 0, 28672, 81408, 162816, 268288, 373760, 421888, 307200, -133120, -1110016, -2834432, -5402624, -8585216, -11501568, -12197888
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,4
|
|
|
COMMENTS
| Diagonal sums of number array A124394.
|
|
|
LINKS
| Alois P. Heinz, Table of n, a(n) for n = 0..1000
|
|
|
FORMULA
| a(n) = sum{k=0..floor(n/2), sum{j=0..k+1, C(k+1,j) C(n-j+1,2k+1) (-2)^j}};
a(n) = term (2,2) in the 3x3 matrix [2,1,0; 0,0,1; -2,0,0]^n. # Alois P. Heinz, Sep 10 2008
|
|
|
MAPLE
| a:= n-> (Matrix([[2, 1, 0], [0, 0, 1], [-2, 0, 0]])^n)[2, 2]: seq (a(n), n=0..35); # Alois P. Heinz, Sep 10 2008
|
|
|
CROSSREFS
| Sequence in context: A160162 A064711 A050865 * A024908 A019442 A048166
Adjacent sequences: A124392 A124393 A124394 * A124396 A124397 A124398
|
|
|
KEYWORD
| easy,sign
|
|
|
AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Oct 30 2006
|
| |
|
|
