A139223 M*(M-1), where M is Mersenne prime A000668(n).

6, 42, 930, 16002, 67084290, 17179475970, 274876334082, 4611686011984936962, 5316911983139663484697699213480296450, 383123885216472214589586754930667236976614368197214210

Offset

1,1

Links

Table of n, a(n) for n=1..10.

Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos".

Formula

a(n)=A000668(n)*(A000668(n)-1).

Crossrefs

Cf. A000668, A036689, A139115, A139116, A139224, A139225, A139226, A139256.

Sequence in context: A074651 A330345 A273922 * A291192 A185222 A179861

Adjacent sequences: A139220 A139221 A139222 * A139224 A139225 A139226

Keyword

nonn

Author

Omar E. Pol, May 10 2008

Extensions

More terms from R. J. Mathar, Jun 24 2009

Status

approved