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A090541
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a(n) = floor((Sum_{r=1..n} r)*(Sum_{r=1..n} 1/r)).
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0
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1, 4, 11, 20, 34, 51, 72, 97, 127, 161, 199, 242, 289, 341, 398, 459, 526, 597, 674, 755, 842, 933, 1030, 1132, 1240, 1352, 1470, 1594, 1723, 1857, 1997, 2142, 2293, 2450, 2612, 2780, 2953, 3132, 3317, 3508, 3704, 3907, 4115, 4328, 4548, 4774, 5006, 5243
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OFFSET
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1,2
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COMMENTS
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For large n, a(n) = floor(n*(n+1)/2)*(log(n) + 0.5772...,(Euler's constant)).
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LINKS
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MAPLE
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a:=n->floor(sum(k, k=1..n)*sum(1/k, k=1..n)):seq(a(n), n=1..56); # Emeric Deutsch, Apr 18 2005
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PROG
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(PARI) a(n) = floor((n*(n+1)/2)*sum(k=1, n, 1/k)); \\ Michel Marcus, Aug 18 2019
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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