A178176 a(n) is the number of central quotients of simple compact Lie groups of dimension n

0, 0, 2, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 1, 3, 0, 0, 0, 0, 0, 4, 0, 0, 2, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 2, 0, 0, 0, 1, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 4

Offset

1,3

Links

Table of n, a(n) for n=1..99.

Example

a(3) = 2 since the 3-dimensional SU(2) has two central quotients: SU(2) and SU(2)/2 = SO(3).
The unusually large value a(78) = 6 is due to the simple Lie groups Spin(13), Sp(6), and E_6 each of dimension 78 and each having two central quotients.

Crossrefs

Sequence in context: A348326 A364213 A051907 * A093569 A073091 A125250

Adjacent sequences: A178173 A178174 A178175 * A178177 A178178 A178179

Keyword

nonn

Author

Andrew Rupinski, Dec 18 2010

Status

approved