A096854 a(n) = A062402(-1+2^n).

1, 3, 12, 15, 72, 91, 312, 255, 1240, 1860, 4123, 5080, 26208, 34200, 93600, 65535, 334368, 416560, 1420800, 1596364, 6146800, 5949696, 20485332, 23788842, 120519630, 194016600, 358132380, 458803800, 1674738000, 2166798816, 6045990912, 4294967295, 22739738112, 37862623140

Offset

1,2

Links

Table of n, a(n) for n=1..34.

Mathematica

Table[DivisorSigma[1, EulerPhi[ -1+2^w]], {w, 1, 30}]

Prog

(PARI) a(n) = sigma(eulerphi(2^n-1)); \\ Michel Marcus, Aug 30 2019

Crossrefs

Cf. A062401, A062402, A053287, A096853-A096856.

Sequence in context: A001196 A330941 A361925 * A013191 A332959 A009783

Adjacent sequences: A096851 A096852 A096853 * A096855 A096856 A096857

Keyword

nonn

Author

Labos Elemer, Jul 19 2004

Extensions

More terms from Michel Marcus, Aug 30 2019

Status

approved