A292432 - OEIS

A292432

Number of normal multisets that cannot be expressed as the multiset-union of a set of sets.

0, 1, 1, 3, 5, 9, 16, 27, 46, 76, 130, 203, 350, 554, 890, 1474, 2285, 3732, 5852, 9297, 14628, 22936, 35903, 55893, 86967, 134585, 207934, 321122, 492634, 757490

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OFFSET

1,4

COMMENTS

A multiset is normal if it spans an initial interval of positive integers. Most normal multisets can be expressed as the multiset-union of a set of sets. For example, {1,1,2,2} is the multiset-union of {{1},{2},{1,2}}.

LINKS

Table of n, a(n) for n=1..30.

EXAMPLE

The a(6) = 9 multisets are: {1,1,1,1,1,1}, {1,1,1,1,1,2}, {1,1,1,1,2,2}, {1,1,1,1,2,3}, {1,1,1,2,2,2}, {1,1,2,2,2,2}, {1,2,2,2,2,2}, {1,2,2,2,2,3}, {1,2,3,3,3,3}.

CROSSREFS

Cf. A049311, A089259, A116540, A283877, A292444.

Sequence in context: A337596 A355115 A023656 * A129973 A382202 A018159

Adjacent sequences: A292429 A292430 A292431 * A292433 A292434 A292435

KEYWORD

nonn,more

AUTHOR

Gus Wiseman, Oct 02 2017

EXTENSIONS

a(11)-a(30) from Bert Dobbelaere, Mar 30 2025

STATUS

approved