|
Search: id:A134680
|
|
|
| A134680 |
|
a(n) = length of the Meta-Fibonacci sequence f(1) = ... = f(n) = 1; f(k)=f(k-f(k-1))+f(k-f(k-n)), if that sequence is only defined for finitely many terms, or 0 if that sequence is infinite. |
|
+0
1
|
|
| 6, 0, 164, 0, 60, 2354, 282, 1336, 100, 1254, 366, 419, 498, 483, 778, 1204, 292, 373, 845, 838, 1118, 2120, 815, 2616, 686, 1195, 745, 1112, 2132, 1588, 754, 1227, 1279, 1661, 716, 2275, 784, 2341, 1874, 1463, 1122, 2800, 1350, 1613, 2279, 1557, 1532
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Such a sequence has finite length when the k-th term becomes greater than k.
The term a(2) = 0 is only conjectural - see A005185. - njas, Nov 07 2007
|
|
LINKS
|
T. D. Noe, Table of n, a(n) for n=1..1000
B. Balamohan, A. Kuznetsov and S. Tanny, On the behavior of a variant of Hofstadter's Q-sequence, J. Integer Sequences, Vol. 10 (2007), #07.7.1.
Index entries for Hofstadter-type sequences
|
|
EXAMPLE
|
a(1) = 6: the f-sequence is defined by f(1) = 1, f(n) = 2f(n-f(n-1)), which gives 1,2,2,4,2,8 but f(7) = 2f(-1) is undefined, so the length is 6.
|
|
MATHEMATICA
|
Table[Clear[a]; a[n_] := a[n] = If[n<=k, 1, a[n-a[n-1]]+a[n-a[n-k]]]; t={1}; n=2; While[n<10000 && a[n-1]<n, AppendTo[t, a[n]]; n++ ]; len=Length[t]; If[len==9999, 0, len], {k, 100}]
|
|
CROSSREFS
|
Cf. A005185, A046700, A063882, A132172, A134679 (sequences for n=2..6).
Adjacent sequences: A134677 A134678 A134679 this_sequence A134681 A134682 A134683
Sequence in context: A085511 A005212 A052679 this_sequence A111372 A122192 A109006
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
T. D. Noe (noe(AT)sspectra.com), Nov 06 2007
|
|
|
Search completed in 0.002 seconds
|
