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A082839 Decimal expansion of the (finite) value of the sum_{ k >= 1, k has no zero digit in base 10 } 1/k. 12
2, 3, 1, 0, 3, 4, 4, 7, 9, 0, 9, 4, 2, 0, 5, 4, 1, 6, 1, 6, 0, 3, 4, 0, 5, 4, 0, 4, 3, 3, 2, 5, 5, 9, 8, 1, 3, 8, 3, 0, 2, 8, 0, 0, 0, 0, 5, 2, 8, 2, 1, 4, 1, 8, 8, 6, 7, 2, 3, 0, 9, 4, 7, 7, 2, 7, 3, 8, 7, 5, 0, 7, 9, 6, 0, 6, 1, 4, 1, 9, 4, 2, 6, 3, 5, 9, 2, 0, 1, 9, 1, 0, 5, 2, 6, 1, 3, 9, 3, 3, 8, 6, 5, 2, 1 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

"The most novel culling of the terms of the harmonic series has to be due to A. J. Kempner, who in 1914 considered what would happen if all terms are removed from it which have a particular digit appearing in their denominators. For example, if we choose the digits 7, we would exclude the terms with denominators such as 7, 27, 173,33779, etc. There are 10 such series, each resulting from the removal of one of the digits 0, 1, 2, ..., 9 and the first question which naturally arises is just what percentage of the terms of the series are we removing by the process?"

"The sum of the reciprocals, 1 + 1/2 + 1/3 + 1/4 + 1/5 + ... [A002387] is unbounded. By taking sufficiently many terms, it can be made as large as one pleases. However, if the reciprocals of all numbers that when written in base 10 contain at least one 0 are omitted, then the sum has the limit, 23.10345... [Boas and Wrench, AMM v78]." - Wells.

REFERENCES

Robert Baillie, Sums of reciprocals of integers missing a given digit, Amer. Math. Monthly, 86 (1979), 372-374.

Paul Halmos, "Problems for Mathematicians, Young and Old", Dolciani Mathematical Expositions, 1991, p. 258.

Julian Havil, Gamma, Exploring Euler's Constant, Princeton University Press, Princeton and Oxford, 2003, page 34.

A. D. Wadhwa, Some convergent subseries of the harmonic series, Amer. Math. Monthly, 85 (1978), 661-663.

David Wells, "The Penguin Dictionary of Curious and Interesting Numbers," Revised Edition, Penguin Books, London, England, 1997.

LINKS

Table of n, a(n) for n=2..106.

Baillie, Revised August 17, 2008, Summing The Curious Series Of Kempner And Irwin [From Robert G. Wilson v, Jun 01 2009]

Wolfram Library Archive, KempnerSums.nb (8.6 KB) - Mathematica Notebook, Summing Kempner's Curious (Slowly-Convergent) Series [From Robert G. Wilson v, Jun 01 2009]

EXAMPLE

23.10344790942054161603...

= 23.10344790942054161603405404332559813830280000528214188672309477... [From Robert G. Wilson v, Jun 01 2009]

MATHEMATICA

(* see the Mmca in Wolfram Library Archive *) [From Robert G. Wilson v, Jun 01 2009]

CROSSREFS

Cf. A002387, A052386, A082830, A082831, A082832, A082833, A082834, A082835, A082836, A082837, A082838.

Sequence in context: A154720 A071501 A004572 * A130717 A137396 A244213

Adjacent sequences:  A082836 A082837 A082838 * A082840 A082841 A082842

KEYWORD

nonn,cons,base

AUTHOR

Robert G. Wilson v, Apr 14 2003

EXTENSIONS

More terms from Robert G. Wilson v, Jun 01 2009

STATUS

approved

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Last modified October 25 10:42 EDT 2014. Contains 248521 sequences.