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A259366
Numbers for which the differences between consecutive divisors (ordered by size) are not distinct.
3
6, 12, 15, 18, 20, 24, 30, 36, 40, 42, 45, 48, 54, 56, 60, 63, 66, 70, 72, 75, 78, 80, 84, 90, 91, 96, 99, 100, 102, 105, 108, 110, 112, 114, 120, 126, 130, 132, 135, 138, 140, 144, 150, 156, 160, 162, 165, 168, 174, 180, 182, 186, 189, 192, 195, 198, 200
OFFSET
1,1
COMMENTS
A060682(a(n)) < A000005(a(n)) - 1.
LINKS
EXAMPLE
. n | A193829(n,*) | A027750(n,*) |
. ----+--------------------+-----------------------+------------
. 10 | {1,3,5} | {1,2,5,10} |
. 11 | {10} | {1,11} |
. 12 | {1,1,1,2,6} | {1,2,3,4,6,12} | a(2) = 12
. 13 | {12} | {1,13} |
. 14 | {1,5,7} | {1,2,7,14} |
. 15 | {2,2,10} | {1,3,5,15} | a(3) = 15
. 16 | {1,2,4,8} | {1,2,4,8,16} |
. 17 | {16} | {1,17} |
. 18 | {1,1,3,3,9} | {1,2,3,6,9,18} | a(4) = 18
. 19 | {18} | {1,19} |
. 20 | {1,2,1,5,10} | {1,2,4,5,10,20} | a(5) = 20
. 21 | {2,4,14} | {1,3,7,21} |
. 22 | {1,9,11} | {1,2,11,22} |
. 23 | {22} | {1,23} |
. 24 | {1,1,1,2,2,4,12} | {1,2,3,4,6,8,12,24} | a(6) = 24
. 25 | {4,20} | {1,5,25} | .
PROG
(Haskell)
a259366 n = a259366_list !! (n-1)
a259366_list = filter (\x -> a060682 x < a000005' x - 1) [2..]
CROSSREFS
Cf. A193829, A027750, A060682, A000005, A060683 (complement), subsequence of A129512.
Sequence in context: A343281 A375611 A129512 * A196391 A343207 A362011
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jun 25 2015
STATUS
approved