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A260633
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Numbers that set new records for the most ordered prime factorizations.
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3
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1, 6, 12, 24, 30, 60, 120, 180, 360, 720, 840, 1080, 1260, 1680, 2160, 2520, 4320, 5040, 7560, 10080, 12600, 15120, 25200, 30240, 45360, 50400, 60480, 75600, 90720, 110880, 120960, 151200, 226800, 277200, 302400, 453600, 604800, 665280, 831600, 907200
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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COMMENTS
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If a prime is a divisor of a(n) it is also a divisor of a(n+1).
A260987(n) = A008480(a(n)). - Reinhard Zumkeller, Nov 18 2015
Hernane and Nicolas named these numbers h-champion numbers (the function h(n) is A008480). - Amiram Eldar, Aug 20 2019
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LINKS
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Amiram Eldar, Table of n, a(n) for n = 1..2011 (terms 1..80 from Reinhard Zumkeller)
Marc Deléglise, Tables des 785 premiers champions de la fonction h(n), alternative link (pdf format).
Mohand-Ouamar Hernane and Jean-Louis Nicolas, Grandes valeurs du nombre de factorisations d’un entier en produit ordonné de facteurs premiers, The Ramanujan Journal, Vol. 14, No. 2 (2007), pp. 277-304, alternative link.
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EXAMPLE
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See A260987.
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MATHEMATICA
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t = {1}~Join~Array[Multinomial @@ Last@ Transpose@ FactorInteger@ # &, 5*10^6, 2]; m = {1}; a = {1}; Do[If[t[[k]] > Max@ m, AppendTo[m, t[[k]]]; AppendTo[a, k]], {k, 2, Length@ t}]; a (* Michael De Vlieger, Nov 12 2015, after Olivier Gérard at A008480 *)
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PROG
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(Haskell)
a260633 n = a260633_list !! (n-1)
-- where a260633_list is defined in A260987.
-- Reinhard Zumkeller, Nov 18 2015
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CROSSREFS
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Record high values of A008480.
Cf. A260987.
Sequence in context: A071611 A216453 A119500 * A110967 A000082 A263849
Adjacent sequences: A260630 A260631 A260632 * A260634 A260635 A260636
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KEYWORD
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nonn
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AUTHOR
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Gordon Hamilton, Nov 11 2015
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EXTENSIONS
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More terms from Michael De Vlieger, Nov 12 2015
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STATUS
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approved
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