A165223 Products of 2 successive Mersenne primes.

21, 217, 3937, 1040257, 1073602561, 68718821377, 1125897758834689, 4951760154835678088235319297, 1427247692705959880439315947500961989719490561

Offset

1,1

Comments

Subsequence of A144856 and of A046528. [From R. J. Mathar, Sep 17 2009]

Links

Table of n, a(n) for n=1..9.

Formula

a(n)=A000668(n)*A000668(n+1). [From R. J. Mathar, Sep 17 2009]

Crossrefs

Sequence in context: A060933 A075282 A228681 * A152161 A008421 A134585

Adjacent sequences: A165220 A165221 A165222 * A165224 A165225 A165226

Keyword

nonn

Author

Boris Hostnik (megpplus(AT)siol.net), Sep 08 2009

Extensions

Extended by R. J. Mathar, Sep 17 2009

Offset corrected by N. J. A. Sloane, Sep 20 2009

Status

approved