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A320304 a(n) is the frequency of MIDI note number n in Hertz, rounded to the nearest integer.

%I A320304 #16 Apr 20 2021 07:46:29
%S A320304 8,9,9,10,10,11,12,12,13,14,15,15,16,17,18,19,21,22,23,24,26,28,29,31,
%T A320304 33,35,37,39,41,44,46,49,52,55,58,62,65,69,73,78,82,87,92,98,104,110,
%U A320304 117,123,131,139,147,156,165,175,185,196,208,220,233,247,262,277,294,311
%N A320304 a(n) is the frequency of MIDI note number n in Hertz, rounded to the nearest integer.
%C A320304 In electronic music, pitch is often given by MIDI note number. The MIDI number of A_4 (440 Hz) is 69; if a note is k semitones higher than A_4, its MIDI note number is 69 + k, and its frequency is 440*2^(k/12) Hz.
%C A320304 Note that audible notes have MIDI note numbers 16 (20.6017 Hz) to 135 (19912.1270 Hz).
%H A320304 Jianing Song, <a href="/A320304/b320304.txt">Table of n, a(n) for n = 0..1023</a>
%H A320304 Wikipedia, <a href="https://en.wikipedia.org/wiki/Scientific_pitch_notation#Table_of_note_frequencies ">Table of note frequencies</a>
%F A320304 a(n) = round(6.875*2^(n/12+1/4)).
%e A320304 MIDI note | Note name | Frequency
%e A320304   number  |           |    (Hz)
%e A320304      0    |   C_{-1}  |   8.1758
%e A320304      1    |  C#_{-1}  |   8.6620
%e A320304      2    |   D_{-1}  |   9.1770
%e A320304      3    |  D#_{-1}  |   9.7227
%e A320304      4    |   E_{-1}  |  10.3009
%e A320304      5    |   F_{-1}  |  10.9134
%e A320304      6    |  F#_{-1}  |  11.5623
%e A320304      7    |   G_{-1}  |  12.2499
%e A320304      8    |  G#_{-1}  |  12.9782
%e A320304      9    |   A_{-1}  |  13.7500
%e A320304     10    |  A#_{-1}  |  14.5676
%e A320304     11    |   B_{-1}  |  15.4339
%e A320304     12    |   C_{0}   |  16.3516
%o A320304 (PARI) a(n) = round(6.875*2^(n/12+1/4))
%Y A320304 Cf. A144488.
%K A320304 nonn,easy
%O A320304 0,1
%A A320304 _Jianing Song_, Oct 10 2018