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A245213
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Numbers n such that A245212(n) < n.
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4
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72, 96, 120, 144, 180, 192, 216, 240, 288, 336, 360, 384, 432, 480, 504, 528, 540, 576, 600, 624, 648, 672, 720, 756, 768, 792, 840, 864, 900, 936, 960, 972, 1008, 1056, 1080, 1120, 1152, 1176, 1200, 1224, 1248, 1260, 1280, 1296, 1320, 1344, 1368, 1440, 1512
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OFFSET
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1,1
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COMMENTS
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Numbers n such that A245212(n) = (n * tau(n)) - Sum_((d<n) | n) (d * tau(d)) < n.
If d are divisors of n then values of sequence A245212(n) are the bending moments at point 0 of static forces of sizes tau(d) operating in places d on the cantilever as the nonnegative number axis of length n with support at point 0 by the schema: A245212(n) = (n * tau(n)) - Sum_((d<n) | n) (d * tau(d)).
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LINKS
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EXAMPLE
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Number 72 is in sequence because A245212(72) = 62 < 72.
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PROG
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(Magma) [n: n in [1..100000] | (2*(n*(#[d: d in Divisors(n)]))-(&+[d*#([e: e in Divisors(d)]): d in Divisors(n)])) lt 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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