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A002392 Decimal expansion of natural logarithm of 10.
(Formerly M0394 N0151)
13
2, 3, 0, 2, 5, 8, 5, 0, 9, 2, 9, 9, 4, 0, 4, 5, 6, 8, 4, 0, 1, 7, 9, 9, 1, 4, 5, 4, 6, 8, 4, 3, 6, 4, 2, 0, 7, 6, 0, 1, 1, 0, 1, 4, 8, 8, 6, 2, 8, 7, 7, 2, 9, 7, 6, 0, 3, 3, 3, 2, 7, 9, 0, 0, 9, 6, 7, 5, 7 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

10 ln 10 ~ 23.0258509299... appears in Bakir Farhi's paper. Abstract: It is well known since A. J. Kempner's work that the series of the reciprocals of the positive integers whose the decimal representation does not contain any digit 9, is convergent. This result was extended by F. Irwin and others to deal with the series of the reciprocals of the positive integers whose the decimal representation contains only a limited quantity of each digit of a given nonempty set of digits. Actually, such series are known to be all convergent. Here, letting S^{(r)} (r in N}) denote the series of the reciprocal of the positive integers whose the decimal representation contains the digit 9 exactly r times, the impressive obtained result is that S^{(r)} tends to 10 log{10} as r tends to infinity! - Jonathan Vos Post, Jul 23 2008

REFERENCES

A. J. Kempner, A curious convergent series, Amer. Math. Monthly 23(1914)48-50.

W. E. Mansell, Tables of Natural and Common Logarithms. Royal Society Mathematical Tables, Vol. 8, Cambridge Univ. Press, 1964, p. 2.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Uhler, Horace S.; Recalculation and extension of the modulus and of the logarithms of 2, 3, 5, 7 and 17. Proc. Nat. Acad. Sci. U. S. A. 26, (1940). 205-212.

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..20000

Bakir Farhi, A curious result related to Kempner's series, Jul 22, 2008.

_Simon Plouffe_, log(10) the natural logatithm of 10 to 2000 digits

_Simon Plouffe_, Plouffe's Inverter, The natural logarithm of 10 to 2000 digits

Eric Weisstein's World of Mathematics, Natural Logarithm of 10

EXAMPLE

2.302585092994045684017991454684364207601101488628772976033327900967572...

PROG

(PARI) { default(realprecision, 20080); x=log(10); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b002392.txt", n, " ", d)); } [From Harry J. Smith, Apr 16 2009]

CROSSREFS

Cf. A016738 (continued fraction).

Sequence in context: A024307 A219864 A194745 * A002708 A167925 A209927

Adjacent sequences:  A002389 A002390 A002391 * A002393 A002394 A002395

KEYWORD

cons,nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified May 19 23:29 EDT 2013. Contains 225436 sequences.