login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A106742 a[n] =a[a[a[a[a[n - a[n-1]]]]]] + a[n - a[n-2]]. 2
1, 1, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

A sixth-order recursion based on Hofstadter's Q-sequence A005185.

Different from A087839 - see comments in that entry.

Different from A106733.

LINKS

Paolo P. Lava, Table of n, a(n) for n = 1..10000

MATHEMATICA

Hofstadter1[1] = Hofstadter1[2] = 1; Hofstadter1[n_Integer?Positive] := Hofstadter1[n] = Hofstadter1[Hofstadter1[Hofstadter1[Hofstadter1[Hofstadter1[n - Hofstadter1[n - 1]]]]]] + Hofstadter1[ n - Hofstadter1[n - 2]]; a = Table[Hofstadter1[n], {n, 1, digits}]

CROSSREFS

Cf. A087842, A005185, A087836, A004001, A087839, A106733.

Sequence in context: A130247 A209869 A087839 * A106733 A087838 A057627

Adjacent sequences:  A106739 A106740 A106741 * A106743 A106744 A106745

KEYWORD

nonn

AUTHOR

Roger L. Bagula, May 30 2005

EXTENSIONS

Edited by N. J. A. Sloane, Jun 15 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 26 16:58 EST 2020. Contains 331280 sequences. (Running on oeis4.)