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A214832 Integer part of A440 piano key frequencies. 4
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 (list; graph; refs; listen; history; text; internal format)
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.

Wikipedia, Piano Key Frequencies

BGfL, A Virtual Keyboard

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 * A050876 A051243 A090043

Adjacent sequences:  A214829 A214830 A214831 * A214833 A214834 A214835

KEYWORD

nonn,fini,full

AUTHOR

Jon Perry, Mar 07 2013

STATUS

approved

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Last modified February 17 20:32 EST 2018. Contains 299297 sequences. (Running on oeis4.)