|
Search: id:A129804
|
|
|
| A129804 |
|
a(0) = 1, a(1) = 2; for n>0, a(2n) = 3a(2n-1) - a(2n-2), a(2n+1) = 3a(2n) - a(2n-1) - a(n-1). |
|
+0
1
|
|
| 1, 2, 5, 12, 31, 79, 206, 534, 1396, 3642, 9530, 24917, 65221, 170667, 446780, 1169467, 3061621, 8014862, 20982965, 54932637, 143814946, 376508559, 985710731, 2580614104, 6756131581, 17687755722, 46307135585, 121233585812
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
MAPLE
|
a:=proc(n) if n=0 or n=1 then n+1 elif n mod 2 = 0 then 3*a(n-1)-a(n-2) else 3*a(n-1)-a(n-2)-a((n-3)/2) fi end: seq(a(n), n=0..30); - Emeric Deutsch (deutsch(AT)duke.poly.edu), May 20 2007
|
|
PROGRAM
|
(PARI) {m=27; v=vector(m+1); v[1]=1; v[2]=2; for(n=2, m, k=3*v[n]-v[n-1]; if(n%2==1, k=k-v[(n-1)/2]); v[n+1]=k); print(v)} /* Klaus Brockhaus, May 20 2007 */
|
|
CROSSREFS
|
Sequence in context: A003089 A112412 A125023 this_sequence A110035 A000635 A077556
Adjacent sequences: A129801 A129802 A129803 this_sequence A129805 A129806 A129807
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Paul Curtz (bpcrtz(AT)free.fr), May 19 2007
|
|
EXTENSIONS
|
More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu) and Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 20 2007
|
|
|
Search completed in 0.002 seconds
|
