|
| |
|
|
A152106
|
|
((9+sqrt4)^n+(9-sqrt4)^n)/2
|
|
1
| |
|
|
1, 9, 85, 837, 8521, 88929, 944605, 10155357, 110061841, 1199150649, 13109949925, 143644498677, 1576134831961, 17309800577169, 190214028328045, 2090997865462797, 22991481397070881, 252839829506640489
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| a(n) = (11^n+7^n)/2. [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 26 2008]
|
|
|
FORMULA
| a(n)=18*a(n-1)-77*a(n-2), n>1 ; a(0)=1, a(1)=9 . G.f.: (1-9*x)/(1-18*x+77*x^2). a(n)=(Sum_{k, 0<=k<=n}A098158(n,k)*9^(2*k)*4^(n-k))/9^n. [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 26 2008]
|
|
|
EXAMPLE
| a(3)=837
|
|
|
CROSSREFS
| Sequence in context: A163308 A160112 A108427 * A142982 A196955 A029711
Adjacent sequences: A152103 A152104 A152105 * A152107 A152108 A152109
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Al Hakanson (hawkuu(AT)gmail.com), Nov 24 2008
|
|
|
EXTENSIONS
| Extended beyond a(6) by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 26 2008
|
| |
|
|
