|
| |
|
|
A147665
|
|
a(n) = a(a(n - 1)) + r(n) for n >= 3, where r(3*k) = a(a(k)), r(3*k+1) = a(a(k)) and r(3*k+2) = a(n-a(k)), with a(0) = 0 and a(1) = a(2) = 1.
|
|
11
|
|
|
|
0, 1, 1, 2, 2, 3, 3, 3, 5, 4, 3, 6, 4, 3, 6, 5, 5, 9, 6, 5, 12, 6, 5, 15, 8, 8, 11, 8, 7, 11, 8, 7, 14, 9, 7, 14, 8, 7, 10, 5, 5, 13, 6, 6, 13, 6, 6, 9, 7, 6, 9, 8, 9, 17, 12, 7, 12, 7, 6, 15, 9, 8, 14, 9, 7, 18, 9, 7, 12, 9, 9, 16, 10, 8, 14, 11, 11, 15, 11, 12, 13, 8, 10, 14, 9, 7, 15, 11, 12, 15
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,4
|
|
|
LINKS
|
G. C. Greubel, Table of n, a(n) for n = 0..1000
|
|
|
FORMULA
|
a(n) = a(a(n - 1)) + r(n) for n >= 3, where r(3*k) = a(a(k)), r(3*k+1) = a(a(k)) and r(3*k+2) = a(n-a(k)), with a(0) = 0 and a(1) = a(2) = 1.
|
|
|
MATHEMATICA
|
a[n_]:= a[n]= If[n<3, Floor[(n+1)/2], a[a[n-1]] + If[Mod[n, 3]<2, a[a[Floor[n/3]]], a[n - a[Floor[n/3]]]]];
Table[f[n], {n, 0, 100}]
|
|
|
PROG
|
(Python)
def A147665(n):
if n <= 2: return [0, 1, 1][n]
elif n % 3 <= 1: return A147665(A147665(n-1)) + A147665(A147665(n//3))
else: return A147665(A147665(n-1)) + A147665(n - A147665(n//3))
print([A147665(n) for n in range(100)]) # Oct 18 2009
|
|
|
CROSSREFS
|
Cf. A004001, A140473, A143089, A143091, A147871.
Sequence in context: A125843 A210957 A306246 * A222820 A301662 A317773
Adjacent sequences: A147662 A147663 A147664 * A147666 A147667 A147668
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Roger L. Bagula, Nov 09 2008
|
|
|
EXTENSIONS
|
Applied OEIS standards to nomenclature - The Assoc. Editors of the OEIS, Oct 18 2009
Name edited by Petros Hadjicostas, Apr 11 2020
|
|
|
STATUS
|
approved
|
| |
|
|
