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Search: id:A039952
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| A039952 |
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Maximum cardinality of finite D0L sequence over an alphabet with n symbols. |
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+0
2
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| 2, 3, 4, 5, 6, 7, 12, 15, 20, 30, 31, 60, 61, 84, 105, 140, 210, 211, 420, 421, 422, 423, 840, 841, 1260, 1261, 1540, 2310, 2520, 4620, 4621, 5460, 5461, 9240
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Note that a(n) is prime for n = 1, 2, 4, 6, 11, 13, 18, 20, 31. - Jonathan Vos Post (jvospost3(AT)gmail.com), Oct 01 2005
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REFERENCES
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O. Osterby, Prime decompositions with minimum sum, Matematisk Institut, Aarhus Universitet, Technical Report DAIMI PB-19, November 1973;
O. Osterby, Prime decompositions with minimum sum, Nordisk Tidskr. Informationsbehandling (BIT) 16 (1976), 451-458;
P. M. B. Vitanyi, Lindenmayer Systems: Structure, Languages and Growth Functions, Mathematisch Centrum, Math. Centre Tracts #96, 1980, p. 25.
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FORMULA
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Max { Prod p^a + d : Sum p^a + d = n }, p prime
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EXAMPLE
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a(11) = 31 because we can write 11 = 1 + 2 + 3 + 5 and 31 = 1+2*3*5
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CROSSREFS
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Sequence in context: A028819 A108948 A107818 this_sequence A129978 A033079 A165305
Adjacent sequences: A039949 A039950 A039951 this_sequence A039953 A039954 A039955
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KEYWORD
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nonn
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AUTHOR
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Jeffrey Shallit (shallit(AT)uwaterloo.ca)
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EXTENSIONS
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First 4 values appear incorrectly in cited references; corrected by JOS
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