A177085 Ceiling(n/3)-abundant numbers.

6, 8, 12, 16, 18, 20, 24, 28, 30, 32, 36, 40, 42, 44, 48, 54, 56, 60, 64, 66, 70, 72, 78, 80, 84, 88, 90, 96, 100, 102, 104, 108, 110, 112, 114, 120, 126, 128, 132, 136, 138, 140, 144, 150, 152, 156, 160, 162, 168, 174, 176, 180, 186, 192, 196, 198, 200

Offset: 1

Author

Vladimir Shevelev, Dec 09 2010

Keywords

• nonn

Comments

For definition, see comment to A175522.

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.

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

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

Programs

PARI

isok(n) = sumdiv(n, d, (d ceil(n/3); \\ Michel Marcus, Feb 08 2016

Sage

is_A177085 = lambda n: sum(ceil(d/3) for d in divisors(n)) > 2*ceil(n/3) # D. S. McNeil, Dec 10 2010