A129511 Numbers such that all differences between distinct divisors occur exactly once.

1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 13, 14, 16, 17, 19, 21, 22, 23, 25, 26, 27, 29, 31, 32, 33, 34, 35, 37, 38, 39, 41, 43, 44, 46, 47, 49, 50, 51, 52, 53, 55, 57, 58, 59, 61, 62, 64, 65, 67, 68, 69, 71, 73, 74, 76, 77, 79, 81, 82, 83, 85, 86, 87, 89, 92, 93, 94, 95, 97, 98, 101, 103

Offset

1,2

Comments

A129510(a(n)) = A066446(a(n)).

a(n) = A174905(n) for n<27, A174905(27)=37 whereas a(27)=35. - Reinhard Zumkeller, Apr 01 2010

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Example

See example for a(33)=44 in A129510.

Prog

(Haskell)
import Data.List.Ordered (isect, union)
a129511 n = a129511_list !! (n-1)
a129511_list = filter (f [] . a027750_row') [1..] where
   f _ [_] = True
   f zs (d:ds) = null (dds `isect` zs) && f (dds `union` zs) ds
                 where dds = map (subtract d) ds
-- Reinhard Zumkeller, Jun 25 2015

Crossrefs

Cf. A027750, A066446, A129510, A129512 (complement), A174905.

Sequence in context: A306528 A116358 A060683 * A174905 A260402 A368087

Adjacent sequences: A129508 A129509 A129510 * A129512 A129513 A129514

Keyword

nonn

Author

Reinhard Zumkeller, Apr 19 2007

Status

approved