A066477 Numbers having just eleven anti-divisors.

137, 143, 157, 158, 175, 193, 202, 238, 262, 270, 275, 280, 283, 293, 305, 319, 337, 346, 367, 388, 390, 391, 402, 403, 412, 418, 428, 435, 446, 451, 455, 465, 468, 488, 490, 493, 494, 501, 507, 508, 525, 533, 540, 542, 562, 570, 580, 587, 588, 592, 595

Offset

1,1

Comments

See A066272 for definition of anti-divisor.

Links

Table of n, a(n) for n=1..51.

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[ # ]] == 11 & ]

Crossrefs

Cf. A066272.

Sequence in context: A189998 A138358 A138329 * A139647 A114645 A057879

Adjacent sequences: A066474 A066475 A066476 * A066478 A066479 A066480

Keyword

nonn

Author

Robert G. Wilson v, Jan 02 2002

Status

approved