|
| |
|
|
A036605
|
|
a(n)=a(n-2)+2*a(n-3)+a(n-4).
|
|
2
| |
|
|
1, 4, 4, 7, 13, 19, 31, 52, 82, 133, 217, 349, 565, 916, 1480, 2395, 3877, 6271, 10147, 16420, 26566, 42985, 69553, 112537, 182089, 294628, 476716, 771343, 1248061, 2019403, 3267463, 5286868, 8554330, 13841197, 22395529, 36236725
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
REFERENCES
| D. E. Knuth, Art of Computer Programming, Vol. 3, Sect. 5.4.2, Eq. (25).
|
|
|
LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (0,1,2,1).
|
|
|
FORMULA
| 3 * [Fibonacci(n+2)/2] + 1. - R. Stephan, Dec 02 2004
a(n) = (A099837(n+2)+A022086(n+2))/2. G.f. ( -1-4*x-3*x^2-x^3 ) / ( (1+x+x^2)*(x^2+x-1) ). - R. J. Mathar, Mar 21 2011
|
|
|
MAPLE
| A036605 := proc(n) option remember; if n <= 0 then 1 else A036605(n-2)+2*A036605(n-3)+A036605(n-4); fi; end;
|
|
|
CROSSREFS
| Cf. A004695.
Sequence in context: A011981 A109544 A187893 * A183541 A115292 A202676
Adjacent sequences: A036602 A036603 A036604 * A036606 A036607 A036608
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
| |
|
|
