From Wikipedia, the free encyclopedia
232 (two hundred [and] thirty-two ) is the
natural number following
231 and preceding
233 .
In mathematics
Natural number
232 is both a
central polygonal number
[1] and a
cake number .
[2]
It is both a
decagonal number
[3] and a centered 11-gonal number.
[4] It is also
a
refactorable number ,
[5]
a Motzkin sum,
[6]
an
idoneal number ,
[7] a
Riordan number and a
noncototient .
[8]
232 is a
telephone number : in a system of seven telephone users, there are 232 different ways of pairing up some of the users.
[9]
[10]
There are also exactly 232 different eight-vertex connected
indifference graphs , and 232
bracelets with eight beads of one color and seven of another.
[11] Because this number has the form 232 = 44 − 4! , it follows that there are exactly 232 different functions from a set of four elements to a proper subset of the same set.
[12]
References
^
Sloane, N. J. A. (ed.).
"Sequence A000124 (Central polygonal numbers (the Lazy Caterer's sequence))" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
^
Sloane, N. J. A. (ed.).
"Sequence A000125 (Cake numbers)" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
^
Sloane, N. J. A. (ed.).
"Sequence A001107 (10-gonal (or decagonal) numbers)" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
^
Sloane, N. J. A. (ed.).
"Sequence A069125 (Centered 11-gonal numbers)" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation. .
^
Sloane, N. J. A. (ed.).
"Sequence A033950 (Refactorable numbers: number of divisors of n divides n)" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
^
Sloane, N. J. A. (ed.).
"Sequence A005043 (Motzkin sums)" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
^
Sloane, N. J. A. (ed.).
"Sequence A000926 (Euler's "numerus idoneus" (or "numeri idonei", or idoneal, or suitable, or convenient numbers))" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
^
Sloane, N. J. A. (ed.).
"Sequence A005278 (Noncototients)" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
^
Sloane, N. J. A. (ed.).
"Sequence A000085 (Number of self-inverse permutations on n letters, also known as involutions)" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
^ Peart, Paul; Woan, Wen-Jin (2000),
"Generating functions via Hankel and Stieltjes matrices" (PDF) , Journal of Integer Sequences , 3 (2), Article 00.2.1,
Bibcode :
2000JIntS...3...21P ,
MR
1778992 , archived from
the original (PDF) on 2015-09-24, retrieved 2014-08-04 .
^
Sloane, N. J. A. (ed.).
"Sequence A007123 (Number of connected unit interval graphs with n nodes)" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
^
Sloane, N. J. A. (ed.).
"Sequence A036679 (n^n - n!)" . The
On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
100,000
1,000,000
10,000,000
100,000,000
1,000,000,000