|
Search: id:A046814
|
|
| |
|
| 1, 2, 8, 37, 179, 881, 4369, 21746, 108444, 541362, 2704158, 13512392, 67534828, 337584992, 1687627800, 8437136085, 42182258715, 210899507685, 1054456597965, 5272139698215, 26360193558735, 131799177579015
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
FORMULA
|
a(n) = C(n) + A046714(n-1) = C(n) + (5^n - A046748(n))/2, C(n) = A000108(n) (Catalan), A046714(-1) := 0; G.f.: c(x)*(1-4*x)/(1-5*x), where c(x) = g.f. for Catalan A000108.
i) Inhomogeneous recursion: a(n) = 5*a(n-1) -3*C(n)/(2*n-1), C(n) = A000108(n) (Catalan). ii) Homogeneous recursion: a(n)=(9*n-1)*a(n-1)/(n+1)-10*(2*n-3)*a(n-2)/(n+1), n >= 2, a(0)=1, a(1)=2.
|
|
CROSSREFS
|
Cf. A046527, A046714, A046748, A000108.
Sequence in context: A020021 A052618 A055142 this_sequence A007857 A047729 A020076
Adjacent sequences: A046811 A046812 A046813 this_sequence A046815 A046816 A046817
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)
|
|
|
Search completed in 0.002 seconds
|
