Hi all, please consider this counting of special combinations:
def C(n, k): return Compositions(n, max_part=k, inner=[k]).cardinality() for n in (0..4): print([C(n, k) for k in (0..n)]) [0] [0, 1] [0, 1, 1] [0, 1, 1, 1] [0, 1, 2, 1, 1] Edge cases are notoriously difficult and error-prone. Maybe a combinatorialist can help me: I suspect the case C(0, 0) to be wrong, it shouldn't be C(0,0) = 0, but C(0,0) = 1. The counted situation looks like this to me: [[0]] [[ ], [[1]]] [[ ], [[1, 1]], [[2]]] [[ ], [[1, 1, 1]], [[2, 1]], [[3]]] [[ ], [[1, 1, 1, 1]], [[2, 2], [2, 1, 1]], [[3, 1]], [[4]]] Peter P.S. Sage 10.1 -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/a1470edb-4d6f-4444-ac10-12f4e307df55n%40googlegroups.com.