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A177085 Ceiling(n/3)-abundant numbers. 1

%I #25 Nov 17 2019 01:45:02

%S 6,8,12,16,18,20,24,28,30,32,36,40,42,44,48,54,56,60,64,66,70,72,78,

%T 80,84,88,90,96,100,102,104,108,110,112,114,120,126,128,132,136,138,

%U 140,144,150,152,156,160,162,168,174,176,180,186,192,196,198,200

%N Ceiling(n/3)-abundant numbers.

%C For definition, see comment to A175522.

%C It appears most terms are even, but there exist odd terms: 945, 1155, 1575, etc. For n < 10^5 there are 211 odd terms of the sequence and 24628 even ones.

%H Amiram Eldar, <a href="/A177085/b177085.txt">Table of n, a(n) for n = 1..10000</a>

%o (Sage) is_A177085 = lambda n: sum(ceil(d/3) for d in divisors(n)) > 2*ceil(n/3) # _D. S. McNeil_, Dec 10 2010

%o (PARI) isok(n) = sumdiv(n, d, (d<n)*ceil(d/3)) > ceil(n/3); \\ _Michel Marcus_, Feb 08 2016

%Y Cf. A177084 (perfect version), A005100, A005101, A175524, A175526, A175811, A175821, A175837, A074206, A177052.

%K nonn

%O 1,1

%A _Vladimir Shevelev_, Dec 09 2010

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Last modified March 28 08:00 EDT 2024. Contains 371235 sequences. (Running on oeis4.)