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A056471
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Number of palindromic structures using a maximum of six different symbols.
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5
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1, 1, 2, 2, 5, 5, 15, 15, 52, 52, 203, 203, 876, 876, 4111, 4111, 20648, 20648, 109299, 109299, 601492, 601492, 3403127, 3403127, 19628064, 19628064, 114700315, 114700315, 676207628, 676207628, 4010090463
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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COMMENTS
| Permuting the symbols will not change the structure.
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REFERENCES
| M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia.
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FORMULA
| Sum stirling2( [(n+1)/2], k) for k from 1 to 6.
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CROSSREFS
| Cf. A056452.
Sequence in context: A205482 A055879 A056470 * A164904 A188164 A083849
Adjacent sequences: A056468 A056469 A056470 * A056472 A056473 A056474
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KEYWORD
| nonn
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AUTHOR
| Marks R. Nester (nesterm(AT)dpi.qld.gov.au)
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