|
| |
|
|
A138269
|
|
a(n+1) is the Hankel transform of C(n)+C(n+2), where C(n)=A000108(n).
|
|
0
|
|
|
|
1, 3, 12, 53, 231, 1000, 4329, 18747, 81188, 351597, 1522639, 6594000, 28556241, 123666803, 535556412, 2319302053, 10044062391, 43497219000, 188370799289, 815766130347, 3532789487188, 15299239691997
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,2
|
|
|
LINKS
|
Table of n, a(n) for n=0..21.
Index to sequences with linear recurrences with constant coefficients, signature (5,-4,5,-1).
|
|
|
FORMULA
|
G.f.: (1-x)^2/(1-5x+4x^2-5x^3+x^4); a(n)=Re(P(2n,I)*CONJ(P(2n+1,I))) where I=sqrt(-1) and P(n,x)=sum{k=0..floor(n/2), C(n-k,k)x^k}.
|
|
|
CROSSREFS
|
Cf. A092886, A138268.
Sequence in context: A007198 A000256 A124202 * A151198 A151199 A151200
Adjacent sequences: A138266 A138267 A138268 * A138270 A138271 A138272
|
|
|
KEYWORD
|
easy,nonn
|
|
|
AUTHOR
|
Paul Barry, Mar 10 2008
|
|
|
STATUS
|
approved
|
| |
|
|
