S-expression: Difference between revisions
m →Sk (square-particulars): linked table where relevant |
m →Mathematical derivation: re-structuring slightly for clarity and for next section |
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= (k<sup>3</sup> + 3k<sup>2</sup>)/( k<sup>3</sup> + 3k<sup>2</sup> - 4 ) | = (k<sup>3</sup> + 3k<sup>2</sup>)/( k<sup>3</sup> + 3k<sup>2</sup> - 4 ) | ||
This result will be useful, so we will refer to it as [Eq. 1]: | |||
'''[Eq. 1]''' Sk/S(k+2) = (k<sup>3</sup> + 3k<sup>2</sup>)/( k<sup>3</sup> + 3k<sup>2</sup> - 4 ) | |||
Note that when k = 2n in [Eq. 1], everything in the numerator and denominator is divisible by 4 because the only instances of k have it raised to a power of 2 or greater meaning there will be a factor of (2n)<sup>2</sup> = 4n<sup>2</sup>, therefore Sk/S(k+2) is superparticular when k is even. | |||
When k = 4n+1 in [Eq. 1], we have to do some work to show the result is superparticular: | |||
Therefore we can replace their occurrences with 4m+1 and 4a+1 respectively, without having to worry about what m and a are (as we know | (4n+1)<sup>3</sup> = (4n)<sup>3</sup> + 3*(4n)<sup>2</sup> + 3*4n + 1 is of the form 4m+1. | ||
(4n+1)<sup>2</sup> = (4n)<sup>2</sup> + 2*4n + 1 is also of the form 4m+1. | |||
Therefore we can replace their occurrences in [Eq. 1] with 4m+1 and 4a+1 respectively, without having to worry about what m and a are (as we only need to know that m and a are positive integers). Therefore to show S(4n+1)/S(4n+3) is superparticular, we plug in k=4n+1 into [Eq. 1] and then do the replacements and simplify to a superparticular, shown below: | |||
S(4n+1)/S(4n+3) = ( (4n+1)<sup>3</sup> + 3(4n+1)<sup>2</sup> )/( (4n+1)<sup>3</sup> + 3(4n+1)<sup>2</sup> - 4 ) | S(4n+1)/S(4n+3) = ( (4n+1)<sup>3</sup> + 3(4n+1)<sup>2</sup> )/( (4n+1)<sup>3</sup> + 3(4n+1)<sup>2</sup> - 4 ) | ||