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A061042 Denominator of 1/16 - 1/n^2. 11
1, 400, 144, 784, 64, 1296, 400, 1936, 18, 2704, 784, 3600, 256, 4624, 1296, 5776, 50, 7056, 1936, 8464, 576, 10000, 2704, 11664, 49, 13456, 3600, 15376, 1024, 17424, 4624, 19600, 81, 21904, 5776, 24336, 1600, 26896, 7056, 29584 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 4..10000

FORMULA

a(n) = 16*n^2 / gcd(16*n^2, n^2-16). - Colin Barker, Jan 13 2014

MATHEMATICA

Denominator/@(1/16-1/Range[4, 50]^2) (* Harvey P. Dale, May 14 2011 *)

PROG

(Haskell)

import Data.Ratio ((%), denominator)

a061042 n = denominator (1%16 - 1%n^2)  -- Reinhard Zumkeller, May 30 2012

(PARI) a(n)=denominator(1/16 - 1/n^2) \\ Charles R Greathouse IV, Feb 07 2017

CROSSREFS

See A061041 for comments, references, links.

Sequence in context: A140892 A115470 A223284 * A223481 A037991 A200837

Adjacent sequences:  A061039 A061040 A061041 * A061043 A061044 A061045

KEYWORD

nonn,frac,nice,easy

AUTHOR

N. J. A. Sloane, May 26 2001

STATUS

approved

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Last modified October 19 03:20 EDT 2019. Contains 328211 sequences. (Running on oeis4.)