|
| |
|
|
A048693
|
|
Generalized Pellian with 2nd term equal to 6.
|
|
3
| |
|
|
1, 6, 13, 32, 77, 186, 449, 1084, 2617, 6318, 15253, 36824, 88901, 214626, 518153, 1250932, 3020017, 7290966, 17601949, 42494864, 102591677, 247678218, 597948113, 1443574444, 3485097001, 8413768446
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
LINKS
| Index entries for sequences related to linear recurrences with constant coefficients
Tanya Khovanova, Recursive Sequences
|
|
|
FORMULA
| a(n)=2*a(n-1)+a(n-2); a(0)=1, a(1)=6.
G.f.: (1+4*x)/(1-2*x-x^2). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 03 2008]
|
|
|
EXAMPLE
| a(n)=[ (5+sqrt(2))(1+sqrt(2))^n-(5-sqrt(2))(1-sqrt(2))^n ]/2*sqrt(2)
|
|
|
MAPLE
| with(combinat): a:=n->4*fibonacci(n-1, 2)+fibonacci(n, 2): seq(a(n), n=1..26); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 04 2008
|
|
|
MATHEMATICA
| a[n_]:=(MatrixPower[{{1, 2}, {1, 1}}, n].{{5}, {1}})[[2, 1]]; Table[a[n], {n, 0, 40}] [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Feb 20 2010]
|
|
|
CROSSREFS
| Cf. A001333, A000129, A048654, A048655.
Sequence in context: A147330 A042607 A084381 * A041068 A037243 A107710
Adjacent sequences: A048690 A048691 A048692 * A048694 A048695 A048696
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Barry E. Williams
|
| |
|
|
