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A137517
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a(0) = 121; for n>0, a(n) = a(n-1) - n + 1.
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1
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121, 121, 120, 118, 115, 111, 106, 100, 93, 85, 76, 66, 55, 43, 30, 16, 1, -15, -32, -50, -69, -89, -110, -132, -155, -179, -204, -230, -257, -285, -314, -344, -375, -407, -440, -474, -509, -545, -582, -620, -659, -699, -740, -782, -825, -869, -914, -960
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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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a(0)=121, a(1)=121, a(2)=120, a(n)=3*a(n-1)-3*a(n-2)+a(n-3). - Harvey P. Dale, Dec 07 2012
G.f.: -(12*x-11)*(10*x-11) / (x-1)^3 . - R. J. Mathar, Nov 07 2015
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MATHEMATICA
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RecurrenceTable[{a[0]==121, a[n]==a[n-1]-n+1}, a, {n, 60}] (* or *) LinearRecurrence[{3, -3, 1}, {121, 121, 120}, 60] (* Harvey P. Dale, Dec 07 2012 *)
CoefficientList[Series[-(12*x - 11)*(10*x - 11)/(x - 1)^3, {x, 0, 50}], x] (* G. C. Greubel, Feb 23 2017 *)
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PROG
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(PARI) my(x='x + O('x^50)); Vec(-(12*x - 11)*(10*x - 11)/(x - 1)^3) \\ G. C. Greubel, Feb 23 2017
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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Frederic Sebastian (frederic.sebastian(AT)gmail.com), Apr 24 2008
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STATUS
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approved
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