1,2

496 is the third perfect number A000396(3) and 31 is the third Mersenne prime A000668(3). For the structure of this sequence and its representation in base 2, see A135653. - Omar E. Pol (info(AT)polprimos.com), Mar 03 2008

Cf. A000396, A000668, A135653.

Sequence in context: A128761 A001591 A003240 this_sequence A010747 A036130 A122169

Adjacent sequences: A018484 A018485 A018486 this_sequence A018488 A018489 A018490

nonn,fini,full

N. J. A. Sloane (njas(AT)research.att.com).

An incorrect g.f. was deleted by N. J. A. Sloane, Sep 16 2009