A077629 Sum of terms in periodic part of continued fraction expansion of square root of -1+2^n.

0, 3, 7, 7, 25, 15, 63, 31, 125, 63, 187, 127, 1081, 255, 1091, 511, 1247, 1023, 11217, 2047, 11999, 4095, 20259, 8191, 66077, 16383, 88609, 32767, 55491, 65535, 284231, 131071, 413199, 262143, 585102, 524287, 3351311, 1048575, 3462843, 2097151

Offset: 1

Author

Labos Elemer, Nov 13 2002

Keywords

• nonn

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..80

Crossrefs

Cf. A077624-A077635.

Programs

Mathematica

Table[Apply[Plus, Last[ContinuedFraction[Sqrt[ -1+2^u]]]], {u, 1, 25}]

Formula

a(2*n) = 2^(n+1) - 1. - Max Alekseyev, May 13 2010

Extensions

a(1) corrected, a(26) and on added by Max Alekseyev, May 13 2010