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A160505
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a(1)=1, a(n) = p*a(n-1), where p is the smallest prime satisfying gcd(n,p)=1.
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1
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1, 3, 6, 18, 36, 180, 360, 1080, 2160, 6480, 12960, 64800, 129600, 388800, 777600, 2332800, 4665600, 23328000, 46656000, 139968000, 279936000, 839808000, 1679616000, 8398080000, 16796160000, 50388480000, 100776960000
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OFFSET
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1,2
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LINKS
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MAPLE
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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:
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
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MATHEMATICA
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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 *)
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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