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A032311 Number of ways to partition n labeled elements into sets of different sizes of at least 2. 1
1, 0, 1, 1, 1, 11, 16, 57, 85, 1507, 2896, 12563, 51074, 138789, 2954407, 7959304, 38908797, 178913747, 1100724688, 3444477663, 114462103390, 358862880667, 2217915340389, 11257750157888, 73465378482214, 515469706792741, 2247201695123581, 98470393431973852 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..698

C. G. Bower, Transforms (2)

FORMULA

"EGJ" (unordered, element, labeled) transform of 0, 1, 1, 1...

MAPLE

b:= proc(n, i) option remember;

      `if`(n=0, 1, `if`(i<2, 0, b(n, i-1)+

      `if`(i>n, 0, b(n-i, i-1)*binomial(n, i))))

    end:

a:= n-> b(n$2):

seq(a(n), n=0..30);  # Alois P. Heinz, May 11 2016

CROSSREFS

Sequence in context: A109307 A128835 A184064 * A032221 A032146 A032051

Adjacent sequences:  A032308 A032309 A032310 * A032312 A032313 A032314

KEYWORD

nonn

AUTHOR

Christian G. Bower

EXTENSIONS

a(0)=1 prepended by Alois P. Heinz, May 11 2016

STATUS

approved

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Last modified August 25 00:27 EDT 2016. Contains 275784 sequences.