A064354 Distinct values arising in the sequence of the least common multiples of the first n composite numbers.
1, 4, 12, 24, 72, 360, 2520, 5040, 55440, 277200, 3603600, 10810800, 21621600, 367567200, 6983776800, 160626866400, 1124388064800, 32607253879200, 1010824870255200, 2021649740510400, 74801040398884800, 224403121196654400
Offset: 1
Keywords
Examples
Different from A003418 and A051451.
Links
- Harry J. Smith, Table of n, a(n) for n = 1..100
Programs
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Mathematica
t=t=Select[ Range[ 1, 200 ], !PrimeQ[ # ] & ] Union[ Table[ Apply[ LCM, Table[ Part[ t, w ], {w, 1, s} ] ], {s, 1, 100} ] ] Join[{1},With[{cmps=Select[Range[100],CompositeQ]},Table[LCM@@Take[cmps,n],{n,Length[cmps]}]]]//Union (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 06 2018 *) -
PARI
{ n=0; b=1; for (m=1, 10^9, if (m>1, if (isprime(m) || (b=lcm(a, m)) == a, next)); write("b064354.txt", n++, " ", a=b); if (n==100, break) ) } \\ Harry J. Smith, Sep 12 2009
Extensions
a(22) from Harry J. Smith, Sep 12 2009
Definition clarified by Harvey P. Dale, Dec 06 2018