OFFSET
1,1
COMMENTS
See A066272 for definition of anti-divisor.
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..500
Jon Perry, The Anti-Divisor
Jon Perry, The Anti-divisor [Cached copy]
Jon Perry, The Anti-divisor: Even More Anti-Divisors [Cached copy]
MATHEMATICA
antid[n_] := Select[ Union[ Join[ Select[ Divisors[2n - 1], OddQ[ # ] && # != 1 & ], Select[ Divisors[2n + 1], OddQ[ # ] && # != 1 & ], 2n/Select[ Divisors[ 2*n], OddQ[ # ] && # != 1 &]]] }, # < n & ]]; Select[ Range[10^5], Length[ antid[ # ]] == 4 & ]
PROG
(Python)
from sympy.ntheory.factor_ import antidivisor_count
A066469_list = [n for n in range(1, 10**3) if antidivisor_count(n) == 4] # Chai Wah Wu, Aug 02 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jan 02 2002
EXTENSIONS
More terms from Chai Wah Wu, Aug 02 2015
STATUS
approved