%I A027750
%S A027750 1,1,2,1,3,1,2,4,1,5,1,2,3,6,1,7,1,2,4,8,1,3,9,1,2,5,10,1,11,1,2,3,4,6,
               12,1,13,1,
%T A027750 2,7,14,1,3,5,15,1,2,4,8,16,1,17,1,2,3,6,9,18,1,19,1,2,4,5,10,20,1,3,7,
               21,1,2,11,
%U A027750 22,1,23,1,2,3,4,6,8,12,24,1,5,25,1,2,13,26,1,3,9,27,1,2,4,7,14,28,1,29
%N A027750 Triangle read by rows in which row n list the divisors of n.
%C A027750 Or, in the list of natural numbers (A000027), replace n by its divisors.
%C A027750 This gives the first elements of the ordered pairs (a,b) a >= 1, b >= 
               1 ordered by their product ab.
%C A027750 Also, row n lists the largest parts of the partitions of n whose parts 
               are not distinct. [From Omar E. Pol (info(AT)polprimos.com), Sep 
               17 2008]
%H A027750 Franklin T. Adams-Watters, <a href="b027750.txt">Rows 1 ... 1000, flattened</
               a>
%H A027750 Franklin T. Adams-Watters, <a href="a027750.txt">Rows 1 to 10000</a>
%H A027750 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Divisor.html">Divisor</a>
%H A027750 O. E. Pol, <a href="http://www.polprimos.com/imagenespub/polpatru.jpg">
               A shell model of partitions</a> [From Omar E. Pol (info(AT)polprimos.com), 
               Sep 17 2008]
%H A027750 O. E. Pol, <a href="http://www.polprimos.com/imagenespub/poldiv3v.jpg">
               A 3D model of the divisors of the natural numbers</a> [From Omar 
               E. Pol (info(AT)polprimos.com), Oct 22 2009]
%H A027750 O. E. Pol, <a href="http://www.polprimos.com/imagenespub/poldiv05.jpg">
               Illustration of initial terms</a> [From Omar E. Pol (info(AT)polprimos.com), 
               Oct 22 2009]
%F A027750 a(A006218(n-1) + k) = k-divisor of n, 1<=k<=A000005(n). - Reinhard Zumkeller 
               (reinhard.zumkeller(AT)gmail.com), May 10 2006
%e A027750 1; 1,2; 1,3; 1,2,4; 1,5; 1,2,3,6; ...
%e A027750 [From Omar E. Pol (info(AT)polprimos.com), Sep 17 2008]
%t A027750 Flatten[ Table[ Flatten [ Divisors[ n ] ], {n, 1, 30} ] ]
%o A027750 (MAGMA) [Divisors(n) : n in [1..20]];
%o A027750 (Other) sage: [divisors(n) for n in xrange(1,30)] # view:[[1], [1, 2], 
               [1, 3], [1, 2, 4], [1, 5], [1, 2, 3, 6], [1, 7], [1, 2, 4, 8], [1, 
               3, 9], [1, 2, 5, 10], [1, 11], [1, 2, 3, 4, 6, 12], [1, 13], [1, 
               2, 7, 14], [1, 3, 5, 15], etc... [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               May 24 2009]
%Y A027750 Cf. A056534, A056538, A027751.
%Y A027750 Cf. A135010, A138121. [From Omar E. Pol (info(AT)polprimos.com), Sep 
               17 2008]
%Y A027750 A161700. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Jun 17 2009]
%Y A027750 Cf. A000005, A163280. [From Omar E. Pol (info(AT)polprimos.com), Oct 
               22 2009]
%Y A027750 Sequence in context: A165416 A057059 A162306 this_sequence A087295 A130517 
               A056951
%Y A027750 Adjacent sequences: A027747 A027748 A027749 this_sequence A027751 A027752 
               A027753
%K A027750 nonn,easy,tabf
%O A027750 1,3
%A A027750 N. J. A. Sloane (njas(AT)research.att.com).
%E A027750 More terms from Scott Lindhurst (ScottL(AT)alumni.princeton.edu)