1,1

a(n) = A000668(2*n).

a(3) = 131071 because the (2*3=6)th Mersenne prime is 131071.

Cf. A000668, A134721.

Adjacent sequences: A134719 A134720 A134721 this_sequence A134723 A134724 A134725

Sequence in context: A034670 A020516 A077585 this_sequence A053713 A077586 A002614

easy,nonn

Omar E. Pol (info(AT)polprimos.com), Nov 11 2007