A076359 a(n) = denominator(n!/phi(n!)).
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
Offset: 1
Links
- Robert Israel, Table of n, a(n) for n = 1..2926
Programs
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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
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Mathematica
dnf[n_]:=With[{nn=n!},Denominator[nn/EulerPhi[nn]]]; Array[dnf,40] (* Harvey P. Dale, Feb 21 2015 *) -
PARI
a(n) = numerator(prod(p=1, n, if (isprime(p),(1-1/p), 1))); \\ Michel Marcus, Jan 28 2014
Comments