Изменения

=== Доказательство ===

<tex dpi = "150">B_{n+m}=\sum_{k=0}^n \sum_{j=1}^m </tex><tex dpi = "150">\left\{{m\atop j}\right\}j^{n-k} \binom{n}{k} B_{k}=</tex><tex dpi = "150">B_{n+m}=\sum_{k=0}^n \sum_{j=0}^m </tex><tex dpi = "150">\left\{{m\atop j}\right\}j^{n-k} \binom{n}{k} B_{k}</tex> т.к. <tex dpi = "150">\left\{{m\atop 0}\right\}=0</tex>