A114493 Decimal expansion of log_10(4).

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

Offset: 0

Author

Eric W. Weisstein, Dec 01 2005

Keywords

• nonn
• cons
• easy

Comments

In engineering (all branches, but particularly electronic and electrical) power and amplitude ratios are measured rigorously in decibels (dB). This constant, with offset 1 (i.e., 6.02... = 10*A114493) is the dB equivalent of a 2:1 amplitude ratio or, equivalently, 4:1 power ratio. - Stanislav Sykora, Dec 11 2013

Examples

			0.602059991...
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Eric Weisstein's World of Mathematics, Catalan Number
• Eric Weisstein's World of Mathematics, Central Binomial Coefficient
• Wikipedia, Decibel
• Index entries for transcendental numbers

Crossrefs

Cf. A000108, A114466.

Cf. decimal expansion of log_10(m): A007524 (m=2), A114490 (m=3), this sequence, A153268 (m=5), A153496 (m=6), A153620 (m=7), A153790 (m=8), A104139 (m=9), A154182 (m=11), A154203 (m=12), A154368 (m=13), A154478 (m=14), A154580 (m=15), A154794 (m=16), A154860 (m=17), A154953 (m=18), A155062 (m=19), A155522 (m=20), A155677 (m=21), A155746 (m=22), A155830 (m=23), A155979 (m=24).

Programs

Maple

log10(4.0) ; # R. J. Mathar, Feb 21 2013

Mathematica

RealDigits[Log[10, 4], 10, 100][[1]] (* Vincenzo Librandi, Sep 10 2013 *)

PARI

log(4)/log(10) \\ Charles R Greathouse IV, Aug 04 2020

Formula

A016627 divided by A002392. Two times A007524. - R. J. Mathar, Feb 21 2013

Equals 1/A154155. - R. J. Mathar, Jul 31 2025