Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A006495
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A006495 Real part of (1+2i)^n.
(Formerly M2880)
+0
12
1, 1, -3, -11, -7, 41, 117, 29, -527, -1199, 237, 6469, 11753, -8839, -76443, -108691, 164833, 873121, 922077, -2521451, -9653287, -6699319, 34867797, 103232189, 32125393, -451910159, -1064447283, 130656229, 5583548873 (list; graph; listen)
OFFSET

0,3

COMMENT

Row sums of the Euler related triangle A117411. Partial sums are A006495. - Paul Barry (pbarry(AT)wit.ie), Mar 16 2006

REFERENCES

G. Berzsenyi, Gaussian Fibonacci numbers, Fib. Quart., 15 (1977), 233-236.

LINKS

Index entries for Gaussian integers and primes

Zerinvary Lajos, Sage Notebooks

FORMULA

a(n)=(1/2)*((1+2I)^n+(1-2I)^n) - Benoit Cloitre (benoit7848c(AT)orange.fr), Oct 28 2002

G.f.: (1-x)/(1-2x+5x^2); a(n)=2a(n-1)-5a(n-2); a(n)=5^(n/2)*cos(n*atan(1/3)+pi*n/4); a(n)=sum{k=0..n, sum{j=0..n-k, C(n,k-j)*C(j,n-k)}*(-4)^(n-k)}; - Paul Barry (pbarry(AT)wit.ie), Mar 16 2006

A000351(n) = a(n)^2 + A006496(n)^2. - Fabrice Baubet (intih(AT)free.fr), May 28 2007

MATHEMATICA

Table[Re[(1+2I)^n], {n, 0, 29}] - Giovanni Resta (g.resta(AT)iit.cnr.it), Mar 28 2006

PROGRAM

sage: [lucas_number2(n, 2, 5)/2 for n in xrange(0, 30)] - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 08 2008

CROSSREFS

Cf. A006496.

Sequence in context: A094900 A083557 A119324 this_sequence A112286 A126261 A050097

Adjacent sequences: A006492 A006493 A006494 this_sequence A006496 A006497 A006498

KEYWORD

sign

AUTHOR

njas

EXTENSIONS

Signs from Christian G. Bower (bowerc(AT)usa.net), Nov 15 1998

Corrected by Giovanni Resta (g.resta(AT)iit.cnr.it), Mar 28 2006

page 1

Search completed in 0.005 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified July 25 07:41 EDT 2008. Contains 142293 sequences.


AT&T Labs Research