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 A076359 a(n) = denominator(n!/phi(n!)). 2
 1, 1, 1, 1, 4, 4, 8, 8, 8, 8, 16, 16, 192, 192, 192, 192, 3072, 3072, 55296, 55296, 55296, 55296, 110592, 110592, 110592, 110592, 110592, 110592, 442368, 442368, 13271040, 13271040, 13271040, 13271040, 13271040, 13271040, 477757440 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 COMMENTS Numerator of Product_{p<=n, p prime} (1 - 1/p). - Franz Vrabec, Jan 28 2014 LINKS Robert Israel, Table of n, a(n) for n = 1..2926 FORMULA a(n) = denominator(A000142(n)/A048855(n)). a(n) = A038110(A036234(n)). - Robert Israel, Oct 18 2018 MAPLE P:= 1: p:= 1:  v:= 1: while p < 100 do q:= nextprime(p);    for i from p to q-1 do A[i]:= v od;    P:= P * (1-1/q);    v:= numer(P);    p:= q; od: seq(A[i], i=1..q-1); # Robert Israel, Oct 18 2018 MATHEMATICA dnf[n_]:=With[{nn=n!}, Denominator[nn/EulerPhi[nn]]]; Array[dnf, 40] (* Harvey P. Dale, Feb 21 2015 *) PROG (PARI) a(n) = numerator(prod(p=1, n, if (isprime(p), (1-1/p), 1))); \\ Michel Marcus, Jan 28 2014 CROSSREFS Cf. A000005, A000142, A036234, A038110, A048855, A076358. Sequence in context: A016712 A333167 A246066 * A105675 A196054 A292135 Adjacent sequences:  A076356 A076357 A076358 * A076360 A076361 A076362 KEYWORD easy,nonn,frac AUTHOR Labos Elemer, Oct 08 2002 STATUS approved

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Last modified April 17 16:12 EDT 2021. Contains 343063 sequences. (Running on oeis4.)