A318836 Product_{d|n, d<n, A007431(d) > 0} prime(A007431(d)), where A007431 is the Möbius transform of Euler's totient function.

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

Antti Karttunen, Table of n, a(n) for n = 1..4096

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));
A318336(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

Adjacent sequences: A318833 A318834 A318835 * A318837 A318838 A318839

Keyword

nonn

Author

Antti Karttunen, Sep 05 2018

Status

approved