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A005510
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a(n) = 1 + a(floor(n/2))*a(ceiling(n/2)) for n > 1, a(1) = 3.
(Formerly M2842)
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0
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3, 10, 31, 101, 311, 962, 3132, 10202, 31412, 96722, 299183, 925445, 3012985, 9809425, 31952665, 104080805, 320465225, 986713745, 3038231465, 9355145285, 28937578127, 89510467490, 276877411436, 856448448026, 2788351903326, 9078078610226, 29555650383626
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OFFSET
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1,1
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COMMENTS
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All terms are congruent to 3 mod 7.
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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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MAPLE
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a:= proc(n) option remember; `if`(n=1, 3,
1+(t->a(t)*a(n-t))(iquo(n, 2)))
end:
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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