Number of exceptional sets of roots of type D_n. Also the number of unordered factorizations of the Coxeter element.
A137207
Number of exceptional sets of roots of type D_n. Also the number of unordered factorizations of the Coxeter element.
Terms
- a(0) =12a(1) =87a(2) =584a(3) =3835a(4) =25008a(5) =162792a(6) =1060048a(7) =6910695a(8) =45119100a(9) =295038315a(10) =1932260256a(11) =12673336052a(12) =83236707232a(13) =547388545740
External references
- oeis: A137207