This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A329213 #12 Aug 21 2023 11:14:55 %S A329213 3,6,9,9,9,4,4,2,2,7,1,1,6,3,4,3,9,8,9,3,3,6,9,5,2,0,9,5,4,2,6,1,4,5, %T A329213 5,3,8,1,7,6,1,5,0,7,5,4,3,6,9,8,5,1,8,4,7,5,7,8,1,9,4,7,7,8,2,8,9,6, %U A329213 6,8,9,2,1,7,9,7,1,6,9,8,5,5,1,8,3,0,2,5,6,1,8 %N A329213 Decimal expansion of the fundamental frequency of the note F#4/Gb4 in hertz. %C A329213 In 12-tone equal temperament, when A4 (the fifth A on the Piano keyboard) is tuned to 440 Hz, the frequency of the note F#4/Gb4 (3 semitones below A4) is 440*2^(-3/12) Hz = 370.0 Hz. %H A329213 Wikipedia, <a href="https://en.wikipedia.org/wiki/Piano_key_frequencies">Piano key frequencies</a> %H A329213 <a href="/index/Mu#music">Index entries for sequences based on music</a> %H A329213 <a href="/index/Al#algebraic_04">Index entries for algebraic numbers, degree 4</a> %F A329213 Equals 220 * 2^(3/4). %e A329213 Frequencies of notes in an octave (Hz): %e A329213 >-------------------------------------------------- %e A329213 | %e A329213 | C4 261.6255653005... (A329207) %e A329213 | +--------------------------------------- %e A329213 >----------| C#4/Db4 277.1826309768... (A329208) %e A329213 | +--------------------------------------- %e A329213 | D4 293.6647679174... (A329209) %e A329213 | +--------------------------------------- %e A329213 >----------| D#4/Eb4 311.1269837220... (A329210) %e A329213 | +--------------------------------------- %e A329213 | E4 329.6275569128... (A329211) %e A329213 | %e A329213 >-------------------------------------------------- %e A329213 | %e A329213 | F4 349.2282314330... (A329212) %e A329213 | +--------------------------------------- %e A329213 >----------| F#4/Gb4 369.9944227116... (this seq) %e A329213 | +--------------------------------------- %e A329213 | G4 391.9954359817... (A329214) %e A329213 | +--------------------------------------- %e A329213 >----------| G#4/Ab4 415.3046975799... (A329215) %e A329213 | +--------------------------------------- %e A329213 | A4 440.0000000000 %e A329213 | +--------------------------------------- %e A329213 >----------| A#4/Bb4 466.1637615180... (A329217) %e A329213 | +--------------------------------------- %e A329213 | B4 493.8833012561... (A329218) %e A329213 | %e A329213 >-------------------------------------------------- %e A329213 [New layout from _Jon E. Schoenfield_, Nov 08 2019] %t A329213 RealDigits[220*Surd[8,4],10,120][[1]] (* _Harvey P. Dale_, May 05 2023 *) %o A329213 (PARI) default(realprecision, 100); 440 * 2^(-3/12) %Y A329213 See the Example section above for the fundamental frequency of some other notes. %K A329213 nonn,easy,cons %O A329213 3,1 %A A329213 _Jianing Song_, Nov 08 2019