A073638 Number of anti-divisors of n (A066272) sets a record.
1, 3, 5, 7, 13, 17, 32, 38, 67, 137, 203, 247, 472, 578, 682, 787, 1463, 2047, 2363, 3465, 5197, 5198, 8662, 13513, 15593, 22522, 22523, 29452, 60638, 67567, 67568, 98753, 112612, 157658, 202702, 337837, 337838, 427927, 713212, 788287, 788288, 1013512
Offset: 1
Keywords
Links
- Donovan Johnson, Table of n, a(n) for n = 1..117 (terms < 5*10^11)
- Jon Perry, Anti-divisors.
- Jon Perry, The Anti-divisor [Cached copy]
- Jon Perry, The Anti-divisor: Even More Anti-Divisors [Cached copy]
Programs
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Mathematica
antid[n_] := Select[ Union[ Join[ Select[ Divisors[2n - 1], OddQ[ # ] && # != 1 &], Select[ Divisors[2n + 1], OddQ[ # ] && # != 1 & ], 2n/Select[ Divisors[ 2n], OddQ[ # ] && # != 1 &]]], # < n &]; a = 0; Do[b = Length[ antid[ n]]; If[b > a, Print[n]; a = b], {n, 1, 1013513}] (* Robert G. Wilson v, Mar 17 2004 *)
Extensions
More terms from Robert G. Wilson v, Mar 17 2004
Comments