A329214 - OEIS

%I #14 Jun 19 2024 03:05:34

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

%T 0,3,5,1,4,3,7,3,5,5,0,9,8,6,3,9,0,5,7,7,4,8,8,8,5,3,0,7,6,5,9,0,8,4,

%U 9,5,5,3,4,5,8,9,3,5,4,9,6,7,6,0,5,1,1,3,3,7,5

%N Decimal expansion of the fundamental frequency of the note G4 in hertz.

%C In 12-tone equal temperament, when A4 (the fifth A on the Piano keyboard) is tuned to 440 Hz, the frequency of the note G4 (2 semitones below A4) is 440*2^(-2/12) Hz = 392.0 Hz.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Piano_key_frequencies">Piano key frequencies</a>

%H <a href="/index/Mu#music">Index entries for sequences based on music</a>

%H <a href="/index/Al#algebraic_06">Index entries for algebraic numbers, degree 6</a>

%F Equals 220 * 2^(5/6).

%e Frequencies of notes in an octave (Hz):

%e    >--------------------------------------------------

%e   |

%e   |  C4                  261.6255653005...  (A329207)

%e   |           +---------------------------------------

%e    >----------| C#4/Db4  277.1826309768...  (A329208)

%e   |           +---------------------------------------

%e   |  D4                  293.6647679174...  (A329209)

%e   |           +---------------------------------------

%e    >----------| D#4/Eb4  311.1269837220...  (A329210)

%e   |           +---------------------------------------

%e   |  E4                  329.6275569128...  (A329211)

%e   |

%e    >--------------------------------------------------

%e   |

%e   |  F4                  349.2282314330...  (A329212)

%e   |           +---------------------------------------

%e    >----------| F#4/Gb4  369.9944227116...  (A329213)

%e   |           +---------------------------------------

%e   |  G4                  391.9954359817...  (this seq)

%e   |           +---------------------------------------

%e    >----------| G#4/Ab4  415.3046975799...  (A329215)

%e   |           +---------------------------------------

%e   |  A4                  440.0000000000

%e   |           +---------------------------------------

%e    >----------| A#4/Bb4  466.1637615180...  (A329217)

%e   |           +---------------------------------------

%e   |  B4                  493.8833012561...  (A329218)

%e   |

%e    >--------------------------------------------------

%e [New layout from _Jon E. Schoenfield_, Nov 08 2019]

%t First[RealDigits[220*2^(5/6), 10, 100]] (* _Paolo Xausa_, Jun 18 2024 *)

%o (PARI) default(realprecision, 100); 440 * 2^(-2/12)

%Y See the Example section above for the fundamental frequency of some other notes.

%K nonn,easy,cons

%O 3,1

%A _Jianing Song_, Nov 08 2019