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

Author

Jon Perry, Mar 07 2013

Keywords

• nonn
• fini
• full

Comments

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

Examples

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

Links

• BGfL, A Virtual Keyboard
• Wikipedia, Piano Key Frequencies
• Wikipedia, Twelfth root of two
• Index entries for sequences based on music

Crossrefs

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

Cf. A254531, A010774.

Programs

Haskell

a214832 = floor . (* 440) . (2 **) . (/ 12) . fromIntegral . subtract 49
-- Reinhard Zumkeller, Nov 23 2014

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));

Formula

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