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:
“His are the quiet steeps of dreamland,
The waters of no-more-pain;
His ram’s bell rings ‘neath an arch of stars,
“Rest, rest, and rest again.””
—Walter De La Mare (1873–1956)
“After a certain number of years our faces become our biographies. We get to be responsible for our faces.”
—Cynthia Ozick (b. 1928)