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A154699
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Terms in A014217 pairwise swapped.
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0
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1, 1, 4, 2, 11, 6, 29, 17, 76, 46, 199, 122, 521, 321, 1364, 842, 3571, 2206, 9349, 5777, 24476, 15126, 64079, 39602, 167761, 103681, 439204, 271442, 1149851, 710646, 3010349, 1860497, 7881196, 4870846, 20633239, 12752042
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OFFSET
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0,3
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COMMENTS
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We can build an auxiliary b(n)=a(n+1)-2a(n) = -1,2,-6,7,..., its bisection b(2n)=a(2n+2)-2a(2n), then take the first differences b(2n+2)-b(2n) = a(2n+4)-3*a(2n+2)+2*a(2n) = -5, -10, -25, -65 and have obtained -A106729(n).
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LINKS
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FORMULA
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a(n)=4*a(n-2)-4*(n-4)+a(n-6). G.f.: (1+x-2x^3-x^4+2x^5)/((1-x)(1+x)(x^2+x-1)(x^2-x-1)). [R. J. Mathar, Jan 23 2009]
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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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