|
Search: id:A147722
|
|
|
| A147722 |
|
Row sums of Riordan array ((1-3x)/(1-4x+x^2), x(1-x)/(1-4x+x^2)). |
|
+0
3
|
|
| 1, 2, 8, 36, 164, 748, 3412, 15564, 70996, 323852, 1477268, 6738636, 30738644, 140215948, 639602452, 2917580364, 13308696916, 60708323852, 276924225428, 1263204479436, 5762173946324, 26284460772748
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
Row sums of A147721.
Hankel transform of a(n) is [1,4,0,0,0,0,0,0,...]. [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Dec 03 2008]
|
|
FORMULA
|
G.f.: (1-3x)/(1-5x+2x^2).
a(n)=5*a(n-1)-2*a(n-2), a(0)=1, a(1)=2. [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 13 2008]
a(n)=(1/2)*[(5/2)+(1/2)*sqrt(17)]^n+(1/2)*[(5/2)-(1/2)*sqrt(17)]^n-(1/34)*[(5/2)+(1/2)*sqrt(17)]^n *sqrt(17)+(1/34)*sqrt(17)*[(5/2)-(1/2)*sqrt(17)]^n, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Nov 18 2008]
|
|
CROSSREFS
|
Sequence in context: A088675 A027743 A152124 this_sequence A089387 A084868 A109980
Adjacent sequences: A147719 A147720 A147721 this_sequence A147723 A147724 A147725
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Paul Barry (pbarry(AT)wit.ie), Nov 11 2008
|
|
|
Search completed in 0.002 seconds
|
