login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A204689 a(n) = n^n (mod 4). 2
1, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0, 3, 0, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Apart from a(0), the same as A109718. [Joerg Arndt, Sep 17 2013]

Periodic for n>0 with period 4 = A174824(4): repeat [1, 0, 3, 0].

LINKS

Table of n, a(n) for n=0..86.

Index entries for linear recurrences with constant coefficients, signature (0,0,0,1).

FORMULA

From Bruno Berselli, Jan 18 2012: (Start)

G.f.: (1+x+3x^3-x^4)/(1-x^4).

a(n) = (1-(-1)^n)*(2+i^(n+1))/2 with i=sqrt(-1), a(0)=1.

a(n) = A109718(n) for n>0. (End)

a(2k) = A000007(k), a(2k+1) = A010684(k). - Wesley Ivan Hurt, Jun 15 2016

MAPLE

A204689:=n->n^n mod 4: seq(A204689(n), n=0..150); # Wesley Ivan Hurt, Jun 15 2016

MATHEMATICA

Table[PowerMod[n, n, 4], {n, 0, 140}]

PROG

(MAGMA) [1] cat &cat [[1, 0, 3, 0]^^30]; // Wesley Ivan Hurt, Jun 15 2016

CROSSREFS

Cf. A000007, A010684, A109718, A174824.

Sequence in context: A101270 A155522 A007524 * A109718 A053385 A213543

Adjacent sequences:  A204686 A204687 A204688 * A204690 A204691 A204692

KEYWORD

nonn,easy

AUTHOR

José María Grau Ribas, Jan 18 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 21 08:47 EDT 2019. Contains 328292 sequences. (Running on oeis4.)