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!)
A153112 a(0) = 0 and a(1)=a(2)=1; a(n) = a(a(n-1)) + a(n-a(n-1)) unless floor( sum_{i=0..n-1} a(i)/2) mod 16*A069705(n) = 1 in which case a(n) = A010882(n). 3
0, 1, 1, 1, 2, 2, 3, 3, 3, 4, 5, 5, 5, 5, 6, 7, 7, 8, 8, 8, 8, 8, 9, 10, 11, 2, 12, 12, 12, 13, 13, 2, 14, 14, 14, 14, 15, 16, 16, 17, 18, 18, 19, 19, 10, 19, 20, 20, 20, 21, 21, 21, 10, 24, 24, 13, 24, 25, 16, 26, 26, 26, 27, 27, 28, 28, 1, 2, 2, 3, 3, 3, 4, 5, 5, 5, 2, 6, 7, 7, 8, 8, 8, 8, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

REFERENCES

Per Bak, "How nature works, the science of self-organized criticality", Springer, New York (1996), pp. 49-64.

LINKS

Table of n, a(n) for n=0..84.

MAPLE

A069705 := proc(n) op(1+(n mod 3), [1, 2, 4]) ; end proc:

A010882 := proc(n) op(1+(n mod 3), [1, 2, 3]) ; end proc:

A153112 := proc(n) option remember; local psu ; if n=0 then 0; elif n<=2 then 1; else psu := add( procname(i), i=0..n-1) ; if floor(psu/2) mod (16*A069705(n)) = 1 then A010882(n) ; else procname(procname(n-1)) +procname(n-procname(n-1)) ; end if; end if; end proc:

seq(A153112(n), n=0..100) ; # R. J. Mathar, Jun 24 2011

MATHEMATICA

Clear[f, n]; f[0] = 0; f[1] = 1; f[2] = 1;

f[n_] := f[n] = If[Mod[ Floor[Sum[f[i], {i, 0, n - 1}]/2], 2^(4 + Mod[n, 3])] == 1, 1 + Mod[n, 3],

f[f[n - 1]] + f[n - f[n - 1]]]; a = Table[f[n], {n, 0, 200}]

CROSSREFS

Cf. A004001, A092550, A136640.

Sequence in context: A269381 A080677 A316628 * A005350 A055037 A227386

Adjacent sequences:  A153109 A153110 A153111 * A153113 A153114 A153115

KEYWORD

nonn

AUTHOR

Roger L. Bagula, Dec 18 2008

EXTENSIONS

Definition cleaned up. - R. J. Mathar, Jun 24 2011

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 July 8 19:01 EDT 2020. Contains 335524 sequences. (Running on oeis4.)