By Andrew V. Sills and Doron Zeilberger
Last update (of this webpage, not of article: May 14, 2016).
But, with modern computer algebra systems (Maple and Mathematica in our case) one can go much further
just using Cayley's original ideas. One should also mention the recent beautiful algorithm of
Augustine Munagi, but our approach is even simpler.
If you want to see EXPLICIT expressions, in n, for the number of partitions of an integer n
into at most m parts, with m between 1 and 60, in terms of QUASI-POLYNOMIALS,
the input
gives you the output web-book.
If you dislike quasi-polynomials, but, like guru George Andrews, love the "integer-part" function
(called "trunc" in Maple), and
want to see EXPLICIT Andrews-style expressions in n, for the number of partitions of an integer n
into at most m parts, with m between 1 and 60, in terms of the four basic operations and "trunc",
the input
gives you the output web-book.
If you want to see EXPLICIT expressions, in n, for the number of partitions of an integer n
whose Durfee square (alias H-index) is k, for 1 ≤ k ≤ 40, in terms of QUASI-POLYNOMIALS,
the input
gives you the output web-book.
If you want to see the first 100 (YES, one hundred!) terms in the asymptotic expansion
of pm(n) for SYMBOLIC m (i.e. valid for every m, as n goes to infinity)
If you want to see the first 80 (YES, eighty!) terms in the asymptotic expansion
of Dk(n) the number of partitions of n whose size-of-side-of-Durfee square (alias H-index) is k,
for SYMBOLIC k (i.e. valid for every k, as n goes to infinity)
If you want to see the first 50000 (YES, fifty thousand!) values of p(n), the number of
(integer) partitions of n,
the input
gives you the output.
Note: the output file was slightly edited so that it can be used for computer-experiments,
the list of size 50000 is called pnTable. You can download
oPARTITIONS9,
go into Maple, "read oPARTITIONS9: " (without the quotes), and to get, for example, p(10001) you type:
If you want to see the first 500000 (YES, half million!) values of p(n), the number of
(integer) partitions of n,
the input
gives you the output.
(Warning: 237MB)
Note: the output file was slightly edited so that it can be used for computer-experiments,
the list of size 500000 is called L. You can download
oPARTITIONS9a,
go into Maple, read oPARTITIONS9a:, and to get, for example, p(100001) you type:
If you want to see a web-book with 36 theorems about Ramanujan-style congruences
for pm(n)
the input
gives you the output.
Added May 14, 2016: If you want to see the first 29 terms of the sequence
p(11^3*13*k+237)/13
that was proved by A.O. Atkin to be integers, (see the wikipedia
article on partitions),
look here.
.pdf
LaTex source
[Appeared in Advances in Applied Mathematics v.48 (2012), 640-645]
First Written: Aug. 21, 2011.
I once said that extreme ugliness is beautiful. Analogously, extreme naiveté is sophisticated!
The present approach uses VERY NAIVE guessing to discover, and PROVE (rigorously!), formulas
(or as Cayley and Sylvester would say, formulae) for
the number of (integer) partitions of n into at most m parts, for m ≤ 70, and of course, one can easily go far beyond.
The core of the idea goes back to Arthur Cayley, and is familiar to any second-semester calculus
student: partial fractions! But dear Arthur could only go so far, so his good buddy, James Joseph Sylvester,
designed a sophisticated theory of "waves" that facilitated hand-calculations.
Added Sept. 17, 2011: Watch the lecture:Part 1,
Part 2
Maple Package
Sample Input and Output for PARTITIONS
pnTable[10001];
L[100001];
Doron Zeilberger's List of Papers