|
Search: id:A077834
|
|
|
| A077834 |
|
Expansion of 1/(1-2*x-2*x^2-3*x^3). |
|
+0
3
|
|
| 1, 2, 6, 19, 56, 168, 505, 1514, 4542, 13627, 40880, 122640, 367921, 1103762, 3311286, 9933859, 29801576, 89404728, 268214185, 804642554, 2413927662, 7241782987, 21725348960, 65176046880, 195528140641, 586584421922, 1759753265766, 5279259797299, 15837779391896
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
FORMULA
|
Convolution of A000244 and A049347. G.f. : 1/((1-3x)(1+x+x^2)); a(n)=sum{k=0..n, 3^k*2sqrt(3)cos(2*pi*(n-k)/3+pi/6)/3}; a(n)=3^(n+2)/13+2sqrt(3)cos(2*pi*n/3+pi/6)/39+2sqrt(3)sin(2*pi*n/3+pi/3)/13. - Paul Barry (pbarry(AT)wit.ie), May 19 2004
A152733/3 [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Dec 11 2008]
|
|
MATHEMATICA
|
k0=k1=0; lst={}; Do[kt=k1; k1=3^n-k1-k0; k0=kt; AppendTo[lst, k1/3], {n, 1, 5!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Dec 11 2008]
|
|
CROSSREFS
|
A152733 [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Dec 11 2008]
Sequence in context: A014559 A027098 A121483 this_sequence A067675 A037512 A111277
Adjacent sequences: A077831 A077832 A077833 this_sequence A077835 A077836 A077837
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com), Nov 17 2002
|
|
|
Search completed in 0.002 seconds
|
