

A141525


A low average ratio switched sequence: a(n)=If[Mod[n, 3] == 0, a(n  2) + a(n  3), If(Mod[n, 4) == 0, a(n  1) + a(n  4), a(n  1), a(n  2)]].


0



0, 1, 1, 1, 1, 1, 2, 2, 3, 4, 4, 4, 8, 8, 8, 16, 24, 24, 40, 40, 64, 80, 80, 80, 160, 160, 160, 320, 480, 480, 800, 800, 1280, 1600, 1600, 1600, 3200, 3200, 3200, 6400, 9600
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OFFSET

1,7


COMMENTS

While appearing to be an "even" output or maybe a "regular" sequence the average ratio limit( using <> as expectation value):
Limit[<a(n+1)/a(n)>,n>Infinity]=1.324717957244746;
real root of x^3x1 ( Padovan/ minimal Pisot root).
I got this by accident I meant to type in:
a[n] = If[Mod[n, 3] == 0, a[n  2] + a[n  3], If[Mod[n, 4] == 0, a[n  1] + a[n  4], a[n  1] + a[n  2]]];
which gives a different result!


REFERENCES

.


LINKS

Table of n, a(n) for n=1..41.


FORMULA

a(n)=If[Mod[n, 3] == 0, a(n  2) + a(n  3), If(Mod[n, 4) == 0, a(n  1) + a(n  4), a(n  1), a(n  2)]].


MATHEMATICA

Clear[a] a[0] = 0; a[1] = 1; a[2] = 1; a[3] = 1; a[n_] := a[n] = If[Mod[n, 3] == 0, a[n  2] + a[n  3], If[Mod[n, 4] == 0, a[n  1] + a[n  4], a[n  1], a[n  2]]]; Table[a[n], {n, 0, 40}]


CROSSREFS

Sequence in context: A208914 A049980 A209698 * A209764 A071475 A112778
Adjacent sequences: A141522 A141523 A141524 * A141526 A141527 A141528


KEYWORD

nonn,uned,tabl


AUTHOR

Roger L. Bagula, Aug 11 2008


STATUS

approved



