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A095988
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Number of Gray codes for partitions of n.
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0
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OFFSET
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1,5
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COMMENTS
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List the partitions of n and form a graph where two partitions are connected if one can be transformed into the other by adding 1 from one element, subtracting 1 from another element and rearranging (if necessary). A Gray code corresponds to a Hamiltonian path through all of the partitions.
Terms a(6) through a(10) are given in the Knuth reference.
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REFERENCES
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D. E. Knuth, The Art of Computer Programming, vol. 4A, Combinatorial Algorithms, (to appear), section 7.2.1.4.
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LINKS
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EXAMPLE
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The partitions of the integer 6 are 111111, 21111, 3111, 2211, 222, 321, 33, 42, 411, 51, 6. Each term is obtained from the previous term by adding 1 to one element, subtracting 1 from another element and rearranging. This is the only way to do it for 6, so a(6)=1.
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CROSSREFS
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KEYWORD
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hard,nonn
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AUTHOR
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STATUS
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approved
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