A329210 - OEIS

A329210

Decimal expansion of the fundamental frequency of the note D#4/Eb4 in hertz.

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

(list; constant; graph; refs; listen; history; text; internal format)

OFFSET

3,1

COMMENTS

In 12-tone equal temperament, when A4 (the fifth A on the Piano keyboard) is tuned to 440 Hz, the frequency of the note D#4/Eb4 (6 semitones below A4) is 440*2^(-6/12) Hz = 311.1 Hz.

LINKS

Table of n, a(n) for n=3..93.

Wikipedia, Piano key frequencies

Index entries for sequences based on music

Index entries for algebraic numbers, degree 2

FORMULA

Equals 220 * sqrt(2).

EXAMPLE

Frequencies of notes in an octave (Hz):

>--------------------------------------------------

| C4 261.6255653005... (A329207)

| +---------------------------------------

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

| +---------------------------------------

| D4 293.6647679174... (A329209)

| +---------------------------------------

>----------| D#4/Eb4 311.1269837220... (this seq)

| +---------------------------------------

| E4 329.6275569128... (A329211)

>--------------------------------------------------

| F4 349.2282314330... (A329212)

| +---------------------------------------

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

| +---------------------------------------

| G4 391.9954359817... (A329214)

| +---------------------------------------

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

| +---------------------------------------

| A4 440.0000000000

| +---------------------------------------

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

| +---------------------------------------

| B4 493.8833012561... (A329218)

>--------------------------------------------------

[New layout from Jon E. Schoenfield, Nov 08 2019]

MATHEMATICA

First[RealDigits[220*Sqrt[2], 10, 100]] (* Paolo Xausa, Jun 18 2024 *)

PROG

(PARI) default(realprecision, 100); 440 * 2^(-6/12)

CROSSREFS

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

Sequence in context: A138361 A030408 A226048 * A325669 A332488 A068153

Adjacent sequences: A329207 A329208 A329209 * A329211 A329212 A329213

KEYWORD

nonn,easy,cons

AUTHOR

Jianing Song, Nov 08 2019

STATUS

approved