A174683 Denominator of 1/16 - 1/n^2.

0, 16, 16, 144, 16, 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, 242, 32400, 8464, 35344, 2304, 38416

Offset

0,2

Comments

The value of a(n)=0 is substituted at the pole n=0.

Extends the Bracket spectrum to negative quantum numbers in the fashion of A061038 (1/4-1/n^2) and A181759 (1/9-1/n^2).

Links

G. C. Greubel, Table of n, a(n) for n = 0..10000

Formula

a(n) = A061042(n), n>=4.

a(n) = LCM[n^2 - 16, 16*n^2]/(n^2 - 16), for n>=5. - G. C. Greubel, Sep 16 2018

Mathematica

Table[If[n == 0, 0, If[n == 4, 16, Denominator[(n^2 - 16)/(4*n)^2]]], {n, 0, 100}] (* G. C. Greubel, Sep 16 2018 *)

Prog

(PARI) for(n=0, 100, print1(if(n==0, 0, if(n==4, 16, denominator((n^2 - 16)/(4*n)^2))), ", ")) \\ G. C. Greubel, Sep 16 2018

Crossrefs

Cf A174680 (numerators).

Sequence in context: A022350 A226068 A230977 * A174994 A175971 A165837

Adjacent sequences: A174680 A174681 A174682 * A174684 A174685 A174686

Keyword

nonn,easy,frac

Author

Paul Curtz, Nov 30 2010

Extensions

Removed a(-4)-a(-1) since a(-n)=a(n) by G. C. Greubel, Sep 16 2018

Status

approved