%I #16 May 04 2022 12:16:24
%S 1,2,4,12,24,48,240,720,5040,10080,20160,221760,665280,8648640,
%T 17297280,294053760,5587021440,27935107200,642507465600,1927522396800,
%U 13492656777600,26985313555200,782574093100800,24259796886124800
%N Smallest highly composite number of the form k*a(n-1) where k is an integer greater than 1.
%C Conjecture: subsequence of A019505.
%H Antti Karttunen, <a href="/A133411/b133411.txt">Table of n, a(n) for n = 1..223</a> (computed from the 10000 term b-file of A002182 prepared from Flammenkamp's data)
%e 6 is not in the sequence because 6 is not a multiple of 4, the previous term.
%o (PARI)
%o sublist_of_first_proper_multiple_terms_of(v) = { my(u=v[1], lista=List(u)); for(i=2,#v,if((v[i]>u)&&!(v[i]%u), u = v[i]; listput(lista,u))); Vec(lista); };
%o v133411 = sublist_of_first_proper_multiple_terms_of(v002182); \\ v002182 contains the terms of A002182.
%o A133411(n) = v133411[n]; \\ _Antti Karttunen_, Jan 10 2020
%Y Cf. A002182, A019505, A328521, A330744 (primorial deflation).
%K nonn
%O 1,2
%A _J. Lowell_, Nov 25 2007
%E a(12)-a(24) from _Donovan Johnson_, Sep 09 2008
|