A121290 a(n) = (2^prime(n) - 8)/24 for n>=2.

0, 1, 5, 85, 341, 5461, 21845, 349525, 22369621, 89478485, 5726623061, 91625968981, 366503875925, 5864062014805, 375299968947541, 24019198012642645, 96076792050570581, 6148914691236517205

Offset: 1

Author

Lekraj Beedassy, Aug 24 2006

Keywords

• nonn
• easy
• less

Comments

Previous name was: (2^(p-3) - 1)/3, where p is an odd prime, i.e., p = A065091.

Crossrefs

Cf. A000043, A000668, A124477, A139479, A139480.

Programs

Mathematica

Table[(2^Prime[n] - 8)/24, {n, 2, 100}] (* Artur Jasinski *)

Extensions

New name from Joerg Arndt, Jul 21 2017