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A093335
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a(0) = 0, a(1) = 1 and for n >= 0, a(n+2) = int(4 * a(n) * a(n+1) / (a(n) + a(n+1))).
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1, 1, 2, 2, 4, 5, 8, 12, 19, 29, 45, 70, 109, 170, 265, 414, 646, 1009, 1575, 2460, 3840, 5997, 9364, 14622, 22833, 35654, 55676, 86940, 135762, 211998, 331047, 516946, 807239, 1260545, 1968408, 3073772, 4799858, 7495231, 11704199, 18276724
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| Harmonic-mean analogue of Fibonacci sequence.
Terms in the Fibonacci sequence are equivalent to twice the arithmetic mean of the previous two terms. Terms in this sequence are floor(twice the harmonic mean of the previous two terms).
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EXAMPLE
| a(5) = 4 because a(5) = int(4 * (a(3) * a(4) / (a(3)+a(4))) = int(16/4) = 4
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CROSSREFS
| Cf. A000045, A093333, A093332.
Sequence in context: A094992 A172128 A079501 * A093333 A116085 A085570
Adjacent sequences: A093332 A093333 A093334 * A093336 A093337 A093338
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KEYWORD
| easy,nonn
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AUTHOR
| Robert A. Stump (rstump_2004(AT)yahoo.com), Apr 25 2004
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