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A074094
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a(1) = 1; for n > 1, a(n) = LCM of next n composite numbers.
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1
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1, 12, 360, 1680, 27720, 1965600, 116396280, 758696400, 18465927480, 3962129371200, 5637782470320, 546077803471200, 592841333318073840, 717574218173821008000, 66020319718147594800, 111304867624125438463200
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OFFSET
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1,2
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COMMENTS
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I.e., "next n composite numbers" following those that were used in computing a(n-1); see Example section. - Jon E. Schoenfield, Mar 18 2018
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LINKS
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FORMULA
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EXAMPLE
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a(2) = lcm(4,6) = 12;
a(3) = lcm(8,9,10) = 360;
a(4) = lcm(12,14,15,16) = 1680.
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MAPLE
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comps:= remove(isprime, [$2..10^4]):
N:= floor((sqrt(9+8*nops(comps))-1)/2):
1, seq(ilcm(op(comps[(n-1)*n/2 .. n*(n+1)/2-1])), n=2..N); # Robert Israel, Jan 13 2016
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MATHEMATICA
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Join[{1}, i = 3; Table[t = {}; c = 0; While[c != n, If[! PrimeQ[i], AppendTo[t, i]; c++]; i++]; LCM @@ t, {n, 2, 16}]] (* Jayanta Basu, Jul 30 2013 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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