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A006874 Mu-atoms of period n on continent of Mandelbrot set.
(Formerly M0535)
+0
3
1, 1, 2, 3, 4, 6, 6, 9, 10, 12, 10, 22, 12, 18, 24, 27, 16, 38, 18, 44, 36, 30, 22, 78, 36, 36, 50, 66, 28, 104, 30, 81, 60, 48, 72, 158, 36, 54, 72, 156, 40, 156, 42, 110, 152, 66, 46, 270, 78, 140, 96, 132, 52, 230, 120, 234, 108, 84, 58, 456, 60, 90, 228, 243, 144, 260 (list; graph; listen)
OFFSET

1,3

REFERENCES

B. B. Mandelbrot, The Fractal Geometry of Nature, Freeman, NY, 1982, p. 183.

R. Penrose, The Emperor's New Mind, Penguin Books, NY, 1991, p. 138.

LINKS

R. P. Munafo, Mu-Ency - The Encyclopedia of the Mandelbrot Set

F. V. Weinstein, Notes on Fibonacci partitions

FORMULA

a(n) = Sum_{ d divides n, d<n} phi(n/d)*a(d), n>1, a(1)=1, where phi is Euler totient function (A000010). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Feb 09 2002

EXAMPLE

a(1)=1, a(2)=a(1), a(3)=2*a(1), a(4)=2*a(1)+a(2), a(5)=4*a(1), a(6)=2*a(1)+2*a(2)+a(3), a(7)=6*a(1), a(8)=4*a(1)+2*a(2)+a(4), a(9)=6*a(1)+2*a(3), a(10)=4*a(1)+4*a(2)+a(5), a(11)=10*a(1), a(12)=4*a(1)+2*a(2)+2*a(3)+2*a(4)+a(6),...

MATHEMATICA

a[1] = 1; a[n_] := a[n] = Block[{d = Most@Divisors@n}, Plus @@ (EulerPhi[n/d]*a /@ d)]; Array[a, 66] (from Robert G. Wilson v (rgwv(at)rgwv.com), Nov 22 2005)

CROSSREFS

Cf. A006875, A006876.

Sequence in context: A094871 A079667 A073061 this_sequence A034890 A009490 A064778

Adjacent sequences: A006871 A006872 A006873 this_sequence A006875 A006876 A006877

KEYWORD

nonn

AUTHOR

mrob(AT)mrob.com (Robert P Munafo)

EXTENSIONS

More terms from Vladeta Jovovic (vladeta(AT)Eunet.yu), Feb 09 2002

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Last modified July 4 18:25 EDT 2008. Contains 140886 sequences.


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