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A318836
Product_{d|n, d<n, A007431(d) > 0} prime(A007431(d)), where A007431 is the Möbius transform of Euler's totient function.
4
1, 2, 2, 2, 2, 4, 2, 4, 4, 10, 2, 8, 2, 22, 20, 12, 2, 28, 2, 20, 44, 46, 2, 48, 10, 62, 28, 44, 2, 100, 2, 84, 92, 94, 110, 112, 2, 118, 124, 300, 2, 484, 2, 92, 700, 146, 2, 1008, 22, 530, 188, 124, 2, 1036, 230, 1452, 236, 206, 2, 2000, 2, 218, 3388, 1596, 310, 2116, 2, 188, 292, 5170, 2, 7056, 2, 298, 5300, 236, 506
OFFSET
1,2
LINKS
FORMULA
a(n) = product_{d|n, d<n} A008578(1+A007431(d)).
For all n >= 1, A056239(a(n)) = A062790(n).
PROG
(PARI)
A007431(n) = sumdiv(n, d, moebius(n/d)*eulerphi(d));
A318836(n) = { my(m=1); fordiv(n, d, if((d<n)&&(A007431(d)!=0), m *= prime(A007431(d)))); (m); };
CROSSREFS
Cf. A007431, A062790, A318837 (rgs-transform).
Cf. also A318838.
Sequence in context: A270438 A347291 A331308 * A003036 A089818 A067025
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 05 2018
STATUS
approved