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Harmonic Expansion


A harmonic expansion of a real number x is a series [n;a,b,c,...] defined by

 x=n+1/2(a+1/3(b+1/4(c+...))),

(Havil 2003, p. 99), where n=|_x_| and |_x_| is the floor function. The coefficients a, b, c, ... are obtained from the fractional part of x by successively multiplying by 2, 3, 4, ..., taking the floor function at each step, and continuing with the new fractional part.

Examples are given in the following table.

cOEISharmonic expansion
eA054977[2, 1, 1, 1, 1, 1, 1, ...]
gammaA096622[0, 1, 0, 1, 4, 1, 4, ...]
piA075874[3, 0, 0, 3, 1, 5, 6, 5, ...]

See also

Continued Fraction, Engel Expansion, Harmonic Series

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References

Havil, J. "Harmonic Expansion." §11.8 in Gamma: Exploring Euler's Constant. Princeton, NJ: Princeton University Press, pp. 98-100, 2003.Sloane, N. J. A. Sequences A054977, A075874, and A096622 in "The On-Line Encyclopedia of Integer Sequences."

Referenced on Wolfram|Alpha

Harmonic Expansion

Cite this as:

Weisstein, Eric W. "Harmonic Expansion." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/HarmonicExpansion.html

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