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A074094 a(1) = 1; for n > 1, a(n) = LCM of next n composite numbers. 1
1, 12, 360, 1680, 27720, 1965600, 116396280, 758696400, 18465927480, 3962129371200, 5637782470320, 546077803471200, 592841333318073840, 717574218173821008000, 66020319718147594800, 111304867624125438463200 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

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

LINKS

Robert Israel, Table of n, a(n) for n = 1..356

FORMULA

for n >= 2, a(n) = lcm(A002808(A000217(n-1)...A000217(n)-1)). - Robert Israel, Jan 13 2016

EXAMPLE

a(2) = lcm(4,6) = 12;

a(3) = lcm(8,9,10) = 360;

a(4) = lcm(12,14,15,16) = 1680.

MAPLE

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

MATHEMATICA

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 *)

CROSSREFS

Cf. A000217, A002808.

Sequence in context: A134800 A053068 A046969 * A012553 A128043 A012431

Adjacent sequences:  A074091 A074092 A074093 * A074095 A074096 A074097

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Aug 20 2002

EXTENSIONS

More terms from Sascha Kurz, Jan 14 2003

Offset corrected by Robert Israel, Jan 13 2016

STATUS

approved

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Last modified September 24 15:28 EDT 2021. Contains 347643 sequences. (Running on oeis4.)