A120905 Real part of (1 + 2i)^(2^n) where i is sqrt(-1).

1, -3, -7, -527, 164833, -98248054847, -3977703802948722503807, -510456831154766758152181998159655209453904127

Offset

0,2

Comments

The next term a(8) has 90 digits and is too large to be displayed here.

Links

Table of n, a(n) for n=0..7.

Formula

a(n) = A006495(2^n).

a(n) = real part of (2 + sqrt(-1))^(2^n) for n >= 0.

Example

a(3) = -527 since (1 + 2i)^8 = (-527 + 336i) = A006495(8).

Maple

a:= n-> Re((1 + 2*I)^(2^n));
seq (a(n), n=0..10);

Mathematica

Table[Re[(1 + 2I)^(2^n)], {n, 0, 8}] (* Stefan Steinerberger, Jul 23 2006 *)

Crossrefs

Cf. A006495.

Sequence in context: A013423 A199365 A153217 * A062599 A101246 A056801

Adjacent sequences: A120902 A120903 A120904 * A120906 A120907 A120908

Keyword

sign

Author

Gary W. Adamson, Jul 14 2006

Extensions

Corrected and extended by Stefan Steinerberger and Emeric Deutsch, Jul 23 2006

Status

approved