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

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

Author

Labos Elemer, Jul 19 2004

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..400

Crossrefs

Cf. A000203, A053287, A062401, A062402, A053287, A096853, A096854, A096855, A096856.

Programs

Mathematica

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

PARI

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

Formula

a(n) = A000203(A053287(n)). - Amiram Eldar, Jun 04 2024

Extensions

More terms from Michel Marcus, Aug 30 2019