A214832 Integer part of A440 piano key frequencies, start with A0 = the 1st key.

27, 29, 30, 32, 34, 36, 38, 41, 43, 46, 48, 51, 55, 58, 61, 65, 69, 73, 77, 82, 87, 92, 97, 103, 110, 116, 123, 130, 138, 146, 155, 164, 174, 184, 195, 207, 220, 233, 246, 261, 277, 293, 311, 329, 349, 369, 391, 415, 440, 466, 493, 523, 554, 587, 622, 659, 698, 739, 783, 830, 880, 932, 987, 1046, 1108, 1174, 1244, 1318, 1396, 1479, 1567, 1661, 1760, 1864, 1975, 2093, 2217, 2349, 2489, 2637, 2793, 2959, 3135, 3322, 3520, 3729, 3951, 4186

Offset

1,1

Comments

A254531(a(k)) = k, k = 1..88. - Reinhard Zumkeller, Feb 04 2015

Links

Table of n, a(n) for n=1..88.

BGfL, A Virtual Keyboard

Wikipedia, Piano Key Frequencies

Wikipedia, Twelfth root of two

Index entries for sequences based on music

Formula

a(n) = floor[2^((n-49)/12)*440] (Hz) for 1 <= n <= 88.

Example

Middle C is 261.626 Hz so a(40) = 261.

Prog

(JavaScript)
for (i=1; i<=88; i++) document.write(Math.floor(Math.pow(2, (i-49)/12)*440)+", ");
(PARI) a(n)=floor(440*2^((n-49)/12));
(Haskell)
a214832 = floor . (* 440) . (2 **) . (/ 12) . fromIntegral . subtract 49
-- Reinhard Zumkeller, Nov 23 2014

Crossrefs

Cf. A059620, A079731, A131062, A101285, A131071.

Cf. A254531, A010774.

Sequence in context: A042509 A042510 A157251 * A090043 A030491 A023742

Adjacent sequences: A214829 A214830 A214831 * A214833 A214834 A214835

Keyword

nonn,fini,full

Author

Jon Perry, Mar 07 2013

Status

approved