Returns the cardinality of the multiplicative partition set for an integer (in PARI/GP)
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/* | |
Returns the number of multiplicative partitions of integer n | |
Ref: https://oeis.org/A001055 | |
https://oeis.org/A162247 | |
https://oeis.org/A162247/a162247.txt | |
Inputs: | |
n: Non-negative integer | |
m: Maximum factor (optional) | |
Output: | |
V: Vector of multiplicative partitions of n | |
Example: | |
mnumbpart(60) = 11 | |
Written by: John Peach 29-Dec-2020 | |
Modified from fcnt function by Michael B. Porter (Oct 29 2009), https://oeis.org/A001055 | |
*/ | |
mnumbpart(n,m = n) = | |
{ | |
local(s); | |
s=0; | |
if(n==1,s=1, | |
fordiv(n,d,if(d>1&d<=m,s=s+mnumbpart(n/d,d))) | |
); | |
return(s); | |
} |
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