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%I #11 May 08 2021 12:24:57
%S 1,3,6,18,36,180,360,1080,2160,6480,12960,64800,129600,388800,777600,
%T 2332800,4665600,23328000,46656000,139968000,279936000,839808000,
%U 1679616000,8398080000,16796160000,50388480000,100776960000
%N a(1)=1, a(n) = p*a(n-1), where p is the smallest prime satisfying gcd(n,p)=1.
%H Harvey P. Dale, <a href="/A160505/b160505.txt">Table of n, a(n) for n = 1..1000</a>
%p A053669 := proc(n) local i,p ; for i from 1 do p := ithprime(i) ; if igcd(n,p) = 1 then return p; end if; end do: end proc:
%p A160505 := proc(n) option remember; if n = 1 then 1; else procname(n-1)*A053669(n) ; end if; end proc: # _R. J. Mathar_, Jul 06 2011
%t sp[{n_,a_}]:=Module[{p=2},While[GCD[n+1,p]!=1,p=NextPrime[p]];{n+1,a*p}]; NestList[sp,{1,1},30][[All,2]] (* _Harvey P. Dale_, May 08 2021 *)
%Y Cf. A053669.
%K easy,nonn
%O 1,2
%A _Masahiko Shin_, May 16 2009
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