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A171872 Triangle read by columns: Distinct classifications of N elements containing exactly R binary partitions. 6
1, 0, 1, 0, 1, 1, 0, 2, 3, 3, 1, 1, 0, 3, 17, 36, 60, 56, 50, 27, 19, 6, 4, 1, 1, 0, 6, 74, 573, 2802, 10087, 26512, 55088, 91984, 130267, 157662, 168890, 158658, 133576, 98804, 65664, 38073, 19963, 9013, 3779 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,8

COMMENTS

The bottom of each column is marked by a single 0 in this sequence. Value is 0 for all (N,R) for which N is greater than 2^R.

See note on efficient computation in A171871.

LINKS

Table of n, a(n) for n=0..44.

R. Munafo, Classifications of N Elements

CROSSREFS

First term in each column is A000055(R+1).

Column 4 shares terms with A034189, column 5 with A034190.

Sequence in context: A021433 A228624 A124798 * A005135 A290003 A139460

Adjacent sequences:  A171869 A171870 A171871 * A171873 A171874 A171875

KEYWORD

nonn,tabf

AUTHOR

Robert Munafo, Jan 21 2010

STATUS

approved

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Last modified October 23 22:26 EDT 2017. Contains 293833 sequences.