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A084964
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Follow n+2 by n. Also solution of a(n+2)=a(n)+1, a(0)=2, a(1)=0.
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26
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2, 0, 3, 1, 4, 2, 5, 3, 6, 4, 7, 5, 8, 6, 9, 7, 10, 8, 11, 9, 12, 10, 13, 11, 14, 12, 15, 13, 16, 14, 17, 15, 18, 16, 19, 17, 20, 18, 21, 19, 22, 20, 23, 21, 24, 22, 25, 23, 26, 24, 27, 25, 28, 26, 29, 27, 30, 28, 31, 29, 32, 30, 33, 31, 34, 32, 35, 33, 36, 34, 37, 35, 38, 36, 39
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OFFSET
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0,1
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LINKS
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FORMULA
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G.f.: (2-2x+x^2)/((1-x)(1-x^2)).
a(2n+1)=n. a(2n)=n+2. a(n+2)=a(n)+1. a(n)=-a(-3-n).
a(n) = floor(n/2)*3 - floor((n-1)/2)*2. - Ross La Haye, Mar 27 2013
E.g.f.: ((4 + x)*cosh(x) - (1 - x)*sinh(x))/2. - Stefano Spezia, Jul 01 2023
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MAPLE
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MATHEMATICA
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Table[{n, n-2}, {n, 2, 40}]//Flatten (* or *) LinearRecurrence[{1, 1, -1}, {2, 0, 3}, 80] (* Harvey P. Dale, Sep 12 2021 *)
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PROG
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(PARI) a(n)=n\2-2*(n%2)+2
(Haskell)
import Data.List (transpose)
a084964 n = a084964_list !! n
a084964_list = concat $ transpose [[2..], [0..]]
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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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EXTENSIONS
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First part of definition adjusted to match offset by Klaus Brockhaus, Nov 23 2009
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STATUS
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approved
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