Sharedsupport / 2015-01-23-nemis-lah-numbers.sagewsOpen in CoCalc
Examples for support purposes...
def lah_gen():   # generator (triangel rows)
    yield [1]
    L, n = [0], 0
    while True:
        L.append(1)
        for k in range(n, 0, -1):
            L[k] = L[k]*(n+k)+L[k-1]
        yield L
        n += 1

def lah_triangle(len):   # triangle as a list of rows
    A = lah_gen()
    return [list(A.next()) for _ in range(len)]

lah_triangle(7)
[[1], [0, 1], [0, 2, 1], [0, 6, 6, 1], [0, 24, 36, 12, 1], [0, 120, 240, 120, 20, 1], [0, 720, 1800, 1200, 300, 30, 1]]
show(graphs.DyckGraph())
d3-based renderer not yet implemented