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A145066
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Partial sums of A002522, starting at n=1.
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5
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2, 7, 17, 34, 60, 97, 147, 212, 294, 395, 517, 662, 832, 1029, 1255, 1512, 1802, 2127, 2489, 2890, 3332, 3817, 4347, 4924, 5550, 6227, 6957, 7742, 8584, 9485, 10447, 11472, 12562, 13719, 14945, 16242, 17612, 19057, 20579, 22180, 23862, 25627
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OFFSET
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1,1
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LINKS
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FORMULA
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a(1) = 2; a(n) = a(n-1) + n^2 + 1 for n > 1.
From Christoph Pacher (christoph.pacher(AT)ait.ac.at), Jul 23 2010: (Start)
a(n) = Sum_{k=1..n} (k^2 + 1).
a(n) = n*(n+1)*(2*n+1)/6 + n. (End)
E.g.f.: (1/6)*x*(12 + 9*x + 2*x^2)*exp(x). - G. C. Greubel, Jul 22 2017
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EXAMPLE
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a(2) = a(1) + 2^2 + 1 = 2 + 4 + 1 = 7; a(3) = a(2) + 3^2 + 1 = 7 + 9 + 1 = 17.
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MATHEMATICA
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PROG
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(PARI) {a=0; for(n=1, 42, print1(a=a+n^2+1, ", "))}
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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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