115 (one hundred
ndfifteen) is the
natural number
In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country").
Numbers used for counting are called '' cardinal ...
following
114 114 may refer to:
*114 (number)
*AD 114
*114 BC
*114 (1st London) Army Engineer Regiment, Royal Engineers, an English military unit
*114 (Antrim Artillery) Field Squadron, Royal Engineers, a Northern Irish military unit
*114 (MBTA bus)
*114 (New Je ...
and preceding
116.
In mathematics
115 has a
square
In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
sum of divisors:
:
There are 115 different
rooted tree
In graph theory, a tree is an undirected graph in which any two vertices are connected by ''exactly one'' path, or equivalently a connected acyclic undirected graph. A forest is an undirected graph in which any two vertices are connected by '' ...
s with exactly eight nodes, 115 inequivalent ways of placing six
rooks
Rook (''Corvus frugilegus'') is a bird of the corvid family. Rook or rooks may also refer to:
Games
*Rook (chess), a piece in chess
*Rook (card game), a trick-taking card game
Military
*Sukhoi Su-25
The Sukhoi Su-25 ''Grach'' (russian: Ð ...
on a 6 × 6
chess board in such a way that no two of the rooks attack each other, and 115 solutions to the
stamp folding problem for a strip of seven stamps.
115 is also a
heptagonal pyramidal number A pyramidal number is a figurate number that represents a pyramid with a polygonal base and a given number of triangular sides. A pyramidal number is the number of points in a pyramid where each layer of the pyramid is an -sided polygon of points. ...
. The 115th
Woodall number
In number theory, a Woodall number (''W'n'') is any natural number of the form
:W_n = n \cdot 2^n - 1
for some natural number ''n''. The first few Woodall numbers are:
:1, 7, 23, 63, 159, 383, 895, … .
History
Woodall numbers were first st ...
,
:
is a
prime number
A prime number (or a prime) is a natural number greater than 1 that is not a Product (mathematics), product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime ...
.
115 is the sum of the first five
heptagonal numbers A heptagonal number is a figurate number that is constructed by combining heptagons with ascending size. The ''n''-th heptagonal number is given by the formula
:H_n=\frac.
The first few heptagonal numbers are:
: 0, 1, 7, 18, 34, 55, 81, 112 ...
.
See also
*
115 (disambiguation)
References
Integers
{{Use dmy dates, date=June 2013