SumTools[Hypergeometric]
RegularGammaForm
construct the regular Gamma-function representation of a hypergeometric term
Calling Sequence
Parameters
Description
Examples
RegularGammaForm(H, n)
H
-
hypergeometric term of n
n
variable
Let H be a hypergeometric term of n, R be the certificate of H, and n0 be an integer such that R has neither a pole nor a zero for all n0≤n. The RegularGammaForm(H,n) calling sequence returns the multiplicative decomposition of the form H⁡n0⁢∏k=n0n−1⁡R⁡k where the product is expressed in terms of a product of the Gamma function of the form Γ⁡n−c where c is a constant and their reciprocals.
with⁡SumToolsHypergeometric:
H≔Product⁡12⁢3⁢k2+6⁢k+4⁢2⁢k+3⁢4⁢k+5⁢k+1⁢4⁢k+3k⁢4⁢k−1⁢2⁢k−1⁢4⁢k−3⁢2⁢k+5⁢k+2⁢3⁢k2+1,k=1..n−1
H≔∏k=1n−1⁡3⁢k2+6⁢k+4⁢2⁢k+3⁢4⁢k+5⁢k+1⁢4⁢k+32⁢k⁢4⁢k−1⁢2⁢k−1⁢4⁢k−3⁢2⁢k+5⁢k+2⁢3⁢k2+1
RegularGammaForm⁡H,n
64⁢π⁢12n⁢Γ⁡n+1−I⁢33⁢Γ⁡n+1+I⁢33⁢Γ⁡n+32⁢Γ⁡n+54⁢Γ⁡n+1⁢Γ⁡n+342n⁢Γ⁡n⁢Γ⁡n−14⁢Γ⁡n−12⁢Γ⁡n−34⁢Γ⁡n+52⁢Γ⁡n+2⁢Γ⁡n−I⁢33⁢Γ⁡n+I⁢33
Compare the number of Gamma-function values returned from RegularGammaForm with that of any one of the four efficient representations of the input hypergeometric term H⁡n:
EfficientRepresentation1⁡H,n
64⁢π⁢14n⁢n2+13⁢n⁢n−14⁢n+12⁢n+14⁢n−12⁢n−34Γ⁡n+52⁢Γ⁡n+2
EfficientRepresentation2⁡H,n
64⁢π⁢14n⁢n2+13⁢n−14⁢n+14⁢n−34n+32⁢n+1⁢Γ⁡n⁢Γ⁡n−12
EfficientRepresentation3⁡H,n
64⁢π⁢14n⁢n−14⁢n2+13⁢n+14⁢n−34⁢nn+32⁢Γ⁡n−12⁢Γ⁡n+2
EfficientRepresentation4⁡H,n
See Also
SumTools[Hypergeometric][EfficientRepresentation]
SumTools[Hypergeometric][MultiplicativeDecomposition]
SumTools[Hypergeometric][RationalCanonicalForm]
SumTools[Hypergeometric][SumDecomposition]
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