147 (number)
147 (one hundred [and] forty-seven) is the natural number following 146 and preceding 148.
In mathematics
147 is the fourth centered icosahedral number. These are a class of figurate numbers that represent points in the shape of a regular icosahedron or alternatively points in the shape of a cuboctahedron, and are magic numbers for the face-centered cubic lattice.<ref>Template:Cite OEIS</ref> Separately, it is also a magic number for the diamond cubic.<ref>Template:Cite OEIS</ref>
It is also the fourth Apéry number <math>a_3</math> following 19, where<ref>Template:Cite OEIS</ref> <math display=block>a_n=\sum_{k=0}^n\binom{n}{k}^2\binom{n+k}{k},</math>
with 147 the composite index of the nineteenth triangle number, 190.<ref>Template:Cite OEIS</ref><ref>Template:Cite OEIS</ref>
There are 147 different ways of representing one as a sum of unit fractions with five terms, allowing repeated fractions,<ref>Template:Cite OEIS</ref> and 147 different self-avoiding polygonal chains of length six using horizontal and vertical segments of the integer lattice.<ref>Template:Cite OEIS</ref>