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A017642
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a(n) = (12*n+10)^2.
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2
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100, 484, 1156, 2116, 3364, 4900, 6724, 8836, 11236, 13924, 16900, 20164, 23716, 27556, 31684, 36100, 40804, 45796, 51076, 56644, 62500, 68644, 75076, 81796, 88804, 96100, 103684, 111556, 119716
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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.: 4*(25 + 46*x + x^2)/(1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n >= 3.
a(n) = 144*n^2 + 240*n + 100.
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EXAMPLE
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a(5) = (12*5+10)^2 = 70^2 = 4900.
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MATHEMATICA
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(12*Range[0, 30]+10)^2 (* or *) LinearRecurrence[{3, -3, 1}, {100, 484, 1156}, 30] (* Harvey P. Dale, May 08 2017 *)
CoefficientList[Series[4*(25 + 46 x + x^2)/(1 - x)^3, {x, 0, 40}], x] (* Wesley Ivan Hurt, Dec 22 2020 *)
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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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