A390640 Decimal expansion of 72 / log(7).

3, 7, 0, 0, 0, 6, 8, 0, 6, 5, 0, 6, 2, 2, 0, 4, 9, 8, 9, 9, 2, 1, 4, 7, 5, 6, 0, 3, 4, 6, 5, 3, 6, 3, 5, 8, 3, 8, 8, 9, 6, 4, 1, 9, 8, 7, 5, 1, 1, 5, 6, 2, 2, 6, 2, 9, 1, 9, 6, 1, 7, 1, 3, 2, 9, 5, 9, 6, 0, 8, 2, 5, 0, 7, 6, 0, 0, 0, 6, 5, 4, 5, 0, 0, 8, 2, 7, 8, 6, 6, 2, 9, 9, 6, 8, 7, 1, 7, 8, 2, 1, 5, 4, 9, 9

Offset

2,1

Comments

The logarithmic mean of natural numbers a = 12 and b = 84. Their harmonic (21), arithmetic (48), quadratic (60) and contraharmonic (75) mean as well as their coefficient of dispersion (27) and population standard deviation (36) are natural numbers while their logarithmic mean = x is as close to a natural number (37) as possible, such that abs(x - round(x)) < 1 / (a * b).

Links

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

Wikipedia, Logarithmic mean.

Formula

Equals 72 / A016630.

Equals (12 - 84) / (log(12) - log(84)).

Equals (12 - 84) / (A016635 - A016707).

Example

37.0006806506220498...

Maple

evalf(72/log(7), 105)

Mathematica

RealDigits[72/Log[7], 10, 105][[1]]

Prog

(PARI) 72/log(7)

Crossrefs

Cf. A016630, A016635, A016707.

Sequence in context: A297530 A394357 A222010 * A152590 A261873 A293525

Adjacent sequences: A390637 A390638 A390639 * A390641 A390642 A390643

Keyword

nonn,cons

Author

Michal Paulovic, Nov 13 2025

Status

approved