a(n) is the number of basic ideals in the standard Borel subalgebra of the untwisted affine Lie algebra sl_n.
A194460
a(n) is the number of basic ideals in the standard Borel subalgebra of the untwisted affine Lie algebra sl_n.
Terms
- a(0) =1a(1) =4a(2) =18a(3) =82a(4) =370a(5) =1648a(6) =7252a(7) =31582a(8) =136338a(9) =584248a(10) =2488156a(11) =10540484a(12) =44450068a(13) =186715072a(14) =781628008a(15) =3262239862a(16) =13579324498a(17) =56391614632a(18) =233686316428a(19) =966556003132
External references
- oeis: A194460