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A025224
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a(n) = floor(Sum_{k=1..n} sqrt(k)).
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12
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0, 1, 2, 4, 6, 8, 10, 13, 16, 19, 22, 25, 29, 32, 36, 40, 44, 48, 52, 57, 61, 66, 70, 75, 80, 85, 90, 95, 101, 106, 112, 117, 123, 129, 134, 140, 146, 152, 159, 165, 171, 178, 184, 191, 197, 204, 211, 218, 224, 231, 239, 246, 253, 260, 268, 275, 282, 290, 298, 305, 313, 321, 329, 337
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OFFSET
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0,3
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COMMENTS
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Shekatkar took Ramanujan's formula for sum of the square roots of first n natural numbers, and generalized to include r-th roots where r is any real number greater than 1, using simple properties of Riemann integrable functions. - Jonathan Vos Post, Apr 05 2012
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LINKS
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FORMULA
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MATHEMATICA
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Floor[Accumulate[Sqrt[Range[0, 70]]]] (* Harvey P. Dale, Apr 23 2022 *)
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PROG
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(PARI) a(n) = floor(sum(k=0, n, sqrt(k))); \\ Michel Marcus, Mar 01 2016
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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