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A245213 Numbers n such that A245212(n) < n. 4
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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)).

LINKS

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

EXAMPLE

Number 72 is in sequence because A245212(72) = 62 < 72.

PROG

(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]

CROSSREFS

Cf. A000005, A100484, A245211, A245212, A245214.

Sequence in context: A063922 A063923 A030025 * A270308 A271329 A307867

Adjacent sequences:  A245210 A245211 A245212 * A245214 A245215 A245216

KEYWORD

nonn

AUTHOR

Jaroslav Krizek, Jul 23 2014

STATUS

approved

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Last modified September 22 10:23 EDT 2020. Contains 337289 sequences. (Running on oeis4.)