%I A051683
%S A051683 1,2,4,6,12,18,24,48,72,96,120,240,360,480,600,720,1440,2160,2880,3600,
%T A051683 4320,5040,10080,15120,20160,25200,30240,35280,40320,80640,120960,
%U A051683 161280,201600,241920,282240,322560,362880,725760,1088640,1451520
%N A051683 Triangle read by rows: a(n,k)=n!*k.
%C A051683 This triangle provides a basis for mapping permutations to natural numbers. 
               For example, associate n!k with the following cycles: (12) (23) (123) 
               (34) (234) (1234) (45) (345) (2345) (12345) etc. - Alford Arnold 
               (Alford1940(AT)aol.com), Sep 29 2006
%e A051683 Table begins
%e A051683 1
%e A051683 2 4
%e A051683 6 12 18
%e A051683 24 48 72 96 ...
%Y A051683 Cf. A000142, row sums give A001286(n+1).
%Y A051683 Sequence in context: A167706 A072121 A060735 this_sequence A167777 A007436 
               A052847
%Y A051683 Adjacent sequences: A051680 A051681 A051682 this_sequence A051684 A051685 
               A051686
%K A051683 easy,nice,nonn,tabl
%O A051683 1,2
%A A051683 Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de)