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:
“Its quick silver bell beating, beating
And down the dark one ruby flare
Pulsing out red light like an artery,”
—Karl Shapiro (b. 1913)
“Among a hundred windows shining
dully in the vast side
of greater-than-palace number such-and-such
one burns
these several years, each night
as if the room within were aflame.”
—Denise Levertov (b. 1923)