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A005595
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States of a dynamic storage system.
(Formerly M1069)
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1
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1, 2, 4, 7, 13, 23, 46, 88, 186, 395, 880, 1989, 4644, 10934, 26210, 63319, 154377, 378443, 933022, 2308956, 5735371, 14286907, 35683814, 89324137, 224057918, 563033978, 1417210456, 3572641303, 9018885121, 22796905055, 57692673962, 146167385344, 370710166434
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OFFSET
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0,2
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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FORMULA
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Also "DIK" (bracelet, indistinct, unlabeled) transform of 2, 1, 1, 1, ...
G.f.: ((2 - 2*x + x^3)/((1 - x)*(1 - x - x^2)) + Sum_{d>0} phi(d)*log((1-x^d)/(1-3*x^d+x^(2*d)))/d)/2. - Andrew Howroyd, Jun 20 2018
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PROG
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(PARI) seq(n)={Vec((2 - 2*x + x^3)/((1 - x)*(1 - x - x^2)) + sum(d=1, n, eulerphi(d)/d*log((1-x^d)/(1-3*x^d+x^(2*d)) + O(x*x^n))))/2} \\ Andrew Howroyd, Jun 20 2018
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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