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A145068
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Zero followed by partial sums of A059100, starting at n=1.
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1
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0, 3, 9, 20, 38, 65, 103, 154, 220, 303, 405, 528, 674, 845, 1043, 1270, 1528, 1819, 2145, 2508, 2910, 3353, 3839, 4370, 4948, 5575, 6253, 6984, 7770, 8613, 9515, 10478, 11504, 12595, 13753, 14980, 16278, 17649, 19095, 20618, 22220, 23903, 25669
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OFFSET
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1,2
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LINKS
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FORMULA
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G.f.: x*(3-3*x+2*x^2)/(1-x)^4.
a(1) = 0; a(n) = sum_{j=1..n-1} A059100(j) = a(n-1) + (n-1)^2 + 2 for n > 1.
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EXAMPLE
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a(2) = a(1) + 1^2 + 2 = 0 + 1 + 2 = 3; a(3) = a(2) + 2^2 + 2 = 3 + 4 + 2 = 9.
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MATHEMATICA
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lst={0}; s=0; Do[s+=n^2+2; AppendTo[lst, s], {n, 5!}]; lst
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PROG
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(PARI) {a=-2; for(n=0, 42, print1(a=a+n^2+2, ", "))}
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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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EXTENSIONS
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STATUS
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approved
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