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A225126
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Central terms of the triangle in A048152.
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5
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0, 1, 4, 2, 7, 3, 10, 4, 13, 5, 16, 6, 19, 7, 22, 8, 25, 9, 28, 10, 31, 11, 34, 12, 37, 13, 40, 14, 43, 15, 46, 16, 49, 17, 52, 18, 55, 19, 58, 20, 61, 21, 64, 22, 67, 23, 70, 24, 73, 25, 76, 26, 79, 27, 82, 28, 85, 29, 88, 30, 91, 31, 94, 32, 97, 33, 100
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OFFSET
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1,3
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COMMENTS
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a(n) = A048152(2*n-1,n), central terms;
also a(n) = A060036(2*n-1,n-1) for n > 1.
a(n+1)=the remainder when n^2 is divided by 2n+1. - J. M. Bergot, Jun 25 2013
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LINKS
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FORMULA
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a(1) = 0, a(2*n) = n and a(2*n+1) = 3*n+1.
a(n) = 2*a(n-2)-a(n-4) for n>5. G.f.: -x^2*(x^3-4*x-1) / ((x-1)^2*(x+1)^2). - Colin Barker, May 01 2013
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PROG
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(Haskell)
a225126 n = a048152 (2 * n - 1) n
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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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