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A060641
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Surround numbers of a length 2n zig-zag.
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1
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161, 257, 373, 509, 665, 841, 1037, 1253, 1489, 1745, 2021, 2317, 2633, 2969, 3325, 3701, 4097, 4513, 4949, 5405, 5881, 6377, 6893, 7429, 7985, 8561, 9157, 9773, 10409, 11065, 11741, 12437, 13153, 13889, 14645, 15421, 16217, 17033
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OFFSET
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2,1
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LINKS
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FORMULA
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a(n) = 10n^2 + 46n + 29 with n > 1.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
G.f.: x^2*(161 - 226*x + 85*x^2)/(1-x)^3. (End)
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MATHEMATICA
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LinearRecurrence[{3, -3, 1}, {161, 257, 373}, 40] (* or *) Table[10x^2+66x+85, {x, 40}] (* Harvey P. Dale, May 26 2013 *)
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PROG
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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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