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A228432
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Sum_{i=1..floor(prime(n)/4)} floor(sqrt(i*prime(n))).
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1
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0, 0, 2, 2, 7, 14, 24, 25, 37, 70, 71, 114, 140, 143, 170, 234, 274, 310, 357, 399, 444, 498, 552, 660, 784, 850, 856, 926, 990, 1064, 1310, 1395, 1564, 1574, 1850, 1859, 2054, 2173, 2277, 2494, 2623, 2730, 2986, 3104, 3234, 3246, 3656, 4085, 4235, 4370
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OFFSET
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1,3
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COMMENTS
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If p = prime(n) in A002145 and n>3, or said differently, if n in A080148 and n>1, then a(n) = A081115(n).
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LINKS
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EXAMPLE
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For n=7, p=17 and a(7) = floor(sqrt(17)) + floor(sqrt(34)) + floor(sqrt(51)) + floor(sqrt(68)) = 4+5+7+8 = 24.
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MATHEMATICA
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Table[p = Prime[n]; Sum[Floor[Sqrt[i*p]], {i, Floor[p/4]}], {n, 100}] (* T. D. Noe, Nov 13 2013 *)
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PROG
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(PARI) a(n) = p = prime(n); sum(i=1, p\4, sqrtint(i*p));
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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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