A228763 a(n) = 2^L(n) - 1, where L(n) is the n-th Lucas number (A000032).

3, 1, 7, 15, 127, 2047, 262143, 536870911, 140737488355327, 75557863725914323419135, 10633823966279326983230456482242756607, 803469022129495137770981046170581301261101496891396417650687

Offset

0,1

Links

Table of n, a(n) for n=0..11.

Formula

a(n) = a(n-1) + a(n-2) + a(n-1) * a(n-2) for n>1, a(0)=3, a(1)=1.

Mathematica

Table[2^LucasL[n] - 1, {n, 0, 15}] (* Bruno Berselli, Sep 03 2013 *)

Prog

(Magma) [2^Lucas(n)-1: n in [0..15]]; // Bruno Berselli, Sep 03 2013
(PARI) a(n)=2^(fibonacci(n-1)+fibonacci(n+1))-1 \\ Charles R Greathouse IV, Sep 03 2013

Crossrefs

Cf. A000032, A063896.

Sequence in context: A218810 A218638 A232295 * A101845 A193606 A221328

Adjacent sequences: A228760 A228761 A228762 * A228764 A228765 A228766

Keyword

nonn

Author

Yeshwant Shivrai Valaulikar, Sep 03 2013

Extensions

More terms from Bruno Berselli, Sep 03 2013

Status

approved