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A283565
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Numbers n such that n = Sum_{k=1..m} (n mod k) for some m.
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2
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0, 1, 2, 7, 8, 9, 10, 13, 15, 19, 22, 23, 25, 31, 37, 49, 51, 52, 57, 72, 95, 98, 100, 133, 140, 146, 152, 158, 168, 189, 196, 212, 315, 348, 376, 383, 396, 407, 416, 451, 452, 497, 521, 541, 548, 551, 568, 583, 586, 592, 593, 657, 663, 683, 729, 780, 784, 794
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OFFSET
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1,3
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COMMENTS
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A283593 gives the least m > 0 as described in the name.
Numbers t such that t and 2*t are both in this sequence are 0, 1, 49, 98, 1249, 2599, 3784, 9565, 10933, ... - Altug Alkan, Mar 11 2017
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LINKS
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EXAMPLE
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(7 mod 1) + (7 mod 2) + (7 mod 3) + (7 mod 4) + (7 mod 5) = 0 + 1 + 1 + 3 + 2 = 7, hence 7 appears in this sequence.
(4 mod 1) + (4 mod 2) + (4 mod 3) + (4 mod 4) = 0 + 0 + 1 + 0 = 1, and (4 mod 1) + (4 mod 2) + (4 mod 3) + (4 mod 4) + (4 mod 5) = 0 + 0 + 1 + 0 + 4 = 5, hence 4 does not appear in this sequence.
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PROG
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(PARI) isok(n) = my (s=0); my (k=1); while (s<n, s += n%k; k++); return (s==n)
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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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