Bell Number

In combinatorics, the nth Bell number, named after Eric Temple Bell, is the number of partitions of a set with n members, or equivalently, the number of equivalence relations on it. Starting with B0 = B1 = 1, the first few Bell numbers are:

1, 1, 2, 5, 15, 52, 203, 877, 4140, 21147, 115975, … (sequence A000110 in OEIS).

(See also breakdown by number of subsets/equivalence classes.)

Read more about Bell Number:  Partitions of A Set, Properties of Bell Numbers, Asymptotic Limit and Bounds, Triangle Scheme For Calculating Bell Numbers, Prime Bell Numbers

Famous quotes containing the words bell and/or number:

    By day thy warning ringing bell to sound its notes,
    By night thy silent signal lamps to swing.
    Walt Whitman (1819–1892)

    Without claiming superiority of intellectual over visual understanding, one is nevertheless bound to admit that the cinema allows a number of æsthetic-intellectual means of perception to remain unexercised which cannot but lead to a weakening of judgment.
    Johan Huizinga (1872–1945)