\begin{definition}[Definition:Bernoulli Numbers/Sequence]
The sequence of '''Bernoulli numbers''' begins:
{{begin-eqn}}
{{eqn | l = B_0
      | r = 1
      | c = 
}}
{{eqn | l = B_1
      | ro= -
      | r = \dfrac 1 2
      | c = 
}}
{{eqn | l = B_2
      | r = \dfrac 1 6
      | c = 
}}
{{eqn | l = B_4
      | ro= -
      | r = \dfrac 1 {30}
      | c = 
}}
{{eqn | l = B_6
      | r = \dfrac 1 {42}
      | c = 
}}
{{eqn | l = B_8
      | ro= -
      | r = \dfrac 1 {30}
      | c = 
}}
{{eqn | l = B_{10}
      | r = \dfrac 5 {66}
      | c = 
}}
{{eqn | l = B_{12}
      | ro= -
      | r = \dfrac {691} {2730}
      | c = 
}}
{{end-eqn}}
The odd index Bernoulli numbers, apart from $B_1$, are all equal to $0$.
{{OEIS-Numerators|A027641}}
{{OEIS-Denominators|A027642}}
{{refactor|Given that there are a number of entries in {{BookReference|Les Nombres Remarquables|1983|François Le Lionnais|author2 = Jean Brette}} directly relating to individual entries in this table, and that there may be interesting things to say about each of the individual entries, it's worth considering whether to split each of the entries into its own page.|level = basic}}
\end{definition}