A066475 Numbers having just nine anti-divisors.

67, 77, 94, 95, 105, 115, 122, 123, 127, 130, 148, 149, 150, 165, 171, 172, 178, 182, 185, 187, 188, 189, 195, 207, 212, 213, 214, 215, 217, 218, 227, 228, 230, 237, 241, 253, 255, 257, 266, 273, 277, 284, 287, 298, 302, 308, 310, 311, 314, 318, 322, 323

Offset

1,1

Comments

See A066272 for definition of anti-divisor.

Links

Table of n, a(n) for n=1..52.

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[10^4], Length[ antid[ # ]] == 9 & ]

Crossrefs

Cf. A066272.

Sequence in context: A043255 A044035 A124476 * A106930 A106929 A173040

Adjacent sequences: A066472 A066473 A066474 * A066476 A066477 A066478

Keyword

nonn

Author

Robert G. Wilson v, Jan 02 2002

Status

approved