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A007058
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Let S denote the palindromes in the language {0,1,2,3,4}*; a(n) = number of words of length n in the language SS.
(Formerly M3936)
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2
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1, 5, 25, 65, 265, 605, 2125, 4345, 14665, 27965, 93025, 171825, 559645, 1015565, 3276725, 5857865, 18734665, 33203045, 105436225, 185546785, 585842065, 1025381485, 3222484125, 5615234265, 17577530845, 30517575605, 95213827825, 164794865465, 512692025285, 885009765485, 2746575977125
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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REFERENCES
| R. Kemp, On the number of words in the language {w in Sigma* | w = w^R }^2, Discrete Math., 40 (1982), 225-234.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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MAPLE
| See A007055.
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CROSSREFS
| Cf. A007055-A007057.
Sequence in context: A179131 A054994 A108403 * A071383 A088959 A018782
Adjacent sequences: A007055 A007056 A007057 * A007059 A007060 A007061
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Mira Bernstein, R. Kemp
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EXTENSIONS
| Entry revised by N. J. A. Sloane, Mar 07 2011
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