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A275781 Number of set partitions of [n] having at least two blocks with equal element sums. 2
0, 0, 0, 1, 3, 9, 43, 209, 1042, 5682, 32875, 200919, 1299092, 8848623, 63108778, 471509591, 3671980053 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Table of n, a(n) for n=0..16.

FORMULA

a(n) = A000110(n) - A275780(n).

EXAMPLE

a(3) = 1: 12|3

a(4) = 3: 12|3|4, 13|2|4, 14|23.

a(5) = 9: 12|3|45, 12|3|4|5, 13|25|4, 13|2|4|5, 14|23|5, 1|23|4|5, 14|2|3|5, 15|24|3, 1|25|34.

CROSSREFS

Cf. A000110, A035470, A275780.

Sequence in context: A141774 A141349 A018427 * A199140 A154606 A232216

Adjacent sequences:  A275778 A275779 A275780 * A275782 A275783 A275784

KEYWORD

nonn,more

AUTHOR

Alois P. Heinz, Aug 08 2016

STATUS

approved

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Last modified March 25 03:50 EDT 2019. Contains 321450 sequences. (Running on oeis4.)