This site is supported by donations to The OEIS Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 Wikipedia, Piano Key Frequencies BGfL, A Virtual Keyboard Wikipedia, Twelfth_root_of_two 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 20 04:21 EST 2019. Contains 319323 sequences. (Running on oeis4.)