A126775 a(n) = phi(n)^2 * d(n) = A000010(n)^2 * A000005(n).

1, 2, 8, 12, 32, 16, 72, 64, 108, 64, 200, 96, 288, 144, 256, 320, 512, 216, 648, 384, 576, 400, 968, 512, 1200, 576, 1296, 864, 1568, 512, 1800, 1536, 1600, 1024, 2304, 1296, 2592, 1296, 2304, 2048, 3200, 1152, 3528, 2400, 3456, 1936, 4232, 2560, 5292, 2400

Offset

1,2

Links

Table of n, a(n) for n=1..50.

Formula

Multiplicative with a(p^e) = (e+1)*(p-1)^2*p^(2*e-2). - Amiram Eldar, Dec 29 2022

Mathematica

Table[EulerPhi[n]^2 DivisorSigma[0, n], {n, 50}] (* Harvey P. Dale, Dec 05 2012 *)

Prog

(Magma) [ EulerPhi(n)*EulerPhi(n)*NumberOfDivisors(n) : n in [1..100] ];

Crossrefs

Cf. A000005, A000010, A064840, A127473

Sequence in context: A265736 A047174 A048074 * A306898 A069185 A037197

Adjacent sequences: A126772 A126773 A126774 * A126776 A126777 A126778

Keyword

easy,nonn,mult

Author

Jonathan Vos Post, May 27 2007

Status

approved