SumTools[Hypergeometric]
MultiplicativeDecomposition
construct the four minimal multiplicative decompositions of a hypergeometric term
Calling Sequence
Parameters
Description
Examples
References
MultiplicativeDecomposition[1](H, n, k)
MultiplicativeDecomposition[2](H, n, k)
MultiplicativeDecomposition[3](H, n, k)
MultiplicativeDecomposition[4](H, n, k)
H
-
hypergeometric term of n
n
variable
k
name
Let H be a hypergeometric term of n. The MultiplicativeDecomposition[i](H,n,k) calling sequence constructs the ith minimal multiplicative decomposition of H of the form H⁡n=W⁡n⁢∏k=n0n−1⁡F⁡k where W⁡n,F⁡n are rational functions of n, degree⁡numer⁡F⁡n and degree⁡denom⁡F⁡n have minimal possible values, for i=1,2,3,4.
If i=1 then degree⁡denom⁡W is minimal.
If i=2 then degree⁡numer⁡W is minimal.
If i=3 then degree⁡numer⁡W+degree⁡denom⁡W is minimal, and degree⁡denom⁡W is minimal.
If i=4 then degree⁡numer⁡W+degree⁡denom⁡W is minimal, and degree⁡numer⁡W is minimal.
If the MultiplicativeDecomposition command is called without an index, the first minimal multiplicative decomposition is constructed.
with⁡SumToolsHypergeometric:
H≔24⁢Product⁡k⁢k+2⁢k−4+212⁢k−3+212⁢k+2+212⁢k+11+212k−3⁢k−22⁢k+6⁢k+12⁢k−1+212⁢k+1+212,k=4..n−1
H≔24⁢∏k=4n−1⁡k⁢k+2⁢k−4+2⁢k−3+2⁢k+2+2⁢k+11+2k−3⁢k−22⁢k+6⁢k+12⁢k−1+2⁢k+1+2
MultiplicativeDecomposition1⁡H,n,k
n+1+22⁢n−12⁢n−22⁢n+1⁢n⁢n+10+2⁢n+9+2⁢n+8+2⁢n+7+2⁢n+6+2⁢n+5+2⁢n+4+2⁢n+3+2⁢n+2+2⁢n+2⁢n−1+2⁢∏k=4n−1⁡k−4+2⁢k−3+2k+12⁢k+6⁢k−330⁢5+22⁢14+2⁢13+2⁢12+2⁢11+2⁢10+2⁢9+2⁢8+2⁢7+2⁢6+2⁢4+2⁢3+2
MultiplicativeDecomposition2⁡H,n,k
15817629155328000⁢2+22⁢1+22⁢4+2⁢3+2⁢2⁢∏k=4n−1⁡k+2+2⁢k+11+2k−3⁢k−22n−2+22⁢n−3+22⁢n+52⁢n+42⁢n+32⁢n+22⁢n+2⁢n−1+2⁢n−4+2⁢n+11⁢n+10⁢n+9⁢n+8⁢n+7⁢n+6⁢n+1⁢n
MultiplicativeDecomposition3⁡H,n,k
2+2⁢1+2⁢n+1+2⁢n−12⁢n−22⁢n+1⁢n⁢∏k=4n−1⁡k−4+2⁢k+11+2k+12⁢k+6⁢k−330⁢5+2⁢n−2+2⁢n−3+2
MultiplicativeDecomposition4⁡H,n,k
12096⁢2+2⁢1+2⁢n+1+2⁢n−1⁢n−2⁢∏k=4n−1⁡k−4+2⁢k+11+2k−3⁢k−2⁢k+125+2⁢n−2+2⁢n−3+2⁢n+5⁢n+4⁢n+3⁢n+2
Abramov, S.A.; Le, H.Q.; and Petkovsek, M. "Rational Canonical Forms and Efficient Representations of Hypergeometric Terms." Proc. ISSAC 2003, pp. 7-14. 2003.
See Also
SumTools[Hypergeometric][EfficientRepresentation]
SumTools[Hypergeometric][RationalCanonicalForm]
SumTools[Hypergeometric][SumDecomposition]
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