OFFSET
1,9
COMMENTS
Note 1 is neither prime nor composite.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..644
EXAMPLE
a(10) = Floor((4*6*8*9*10)/(2*3*5*7)) = 82.
MAPLE
a := 1:b := 1:for i from 2 to 100 do if isprime(i) then a := a*i: else b := b*i:fi: c[i] := floor(b/a):od:c[1] := 1:seq(c[j], j=1..100);
MATHEMATICA
Table[t1 = Select[x = Range[n], PrimeQ]; Floor[Divide @@ Times @@@ {Complement[x, t1], t1}], {n, 32}] (* Jayanta Basu, Jul 06 2013 *)
Module[{upto=40, pr, cm}, pr=Prime[Range[PrimePi[upto]]]; cm=Select[ Range[ upto], CompositeQ]; Table[ Floor[Times@@Select[cm, #<=n&]/ Times@@ Select[ pr, #<=n&]], {n, upto}]] (* Harvey P. Dale, Nov 03 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Aug 12 2002
EXTENSIONS
More terms from Sascha Kurz, Aug 15 2002
STATUS
approved