login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A087842 a(n) = a(a(a(n - a(n-1)))) + a(n - a(n-2)). 3
1, 1, 2, 3, 3, 3, 4, 4, 4, 4, 6, 5, 6, 6, 6, 6, 8, 7, 8, 8, 8, 8, 8, 8, 11, 9, 9, 11, 11, 11, 11, 11, 11, 11, 11, 14, 12, 11, 12, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 17, 15, 14, 14, 17, 17, 15, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 21, 18, 17, 17, 21, 20, 17, 21, 21, 21, 18, 21 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
A fourth-order recursive version of Hofstadter Q of the first term of A005185.
LINKS
MATHEMATICA
digits=200 Hofstadter[n_Integer?Positive] := Hofstadter[n] = Hofstadter[Hofstadter[Hofstadter[n - Hofstadter[n-1]]]] + Hofstadter[n - Hofstadter[n-2]] Hofstadter[1] = Hofstadter[2] = 1 a1=Table[Hofstadter[n], {n, 1, digits}]
CROSSREFS
Cf. A005185.
Sequence in context: A057627 A013940 A029129 * A201206 A101776 A189721
KEYWORD
nonn
AUTHOR
Roger L. Bagula, Oct 07 2003
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 08:22 EDT 2024. Contains 371236 sequences. (Running on oeis4.)