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

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A131081 Periodic sequence (8, 7, 4, 1, 0, 1, 4, 7). 5
8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Fourth column of triangular array T defined in A131074.

LINKS

Table of n, a(n) for n=1..105.

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

FORMULA

a(1) = 8, a(2) = a(8) = 7, a(3) = a(7) = 4, a(4) = a(6) = 1, a(5) = 0; for n > 8, a(n) = a(n-8).

G.f.: (8-x-3*x^2-3*x^3+7*x^4)/((1-x)*(1+x^4)).

a(n)=1/56*{(n mod 8)-13*[(n+1) mod 8]-13*[(n+2) mod 8]+[(n+3) mod 8]+15*[(n+4) mod 8]+29*[(n+5) mod 8]+29*[(n+6) mod 8]+15*[(n+7) mod 8]}, with n>=0. - Paolo P. Lava, Jun 19 2007

MATHEMATICA

PadRight[{}, 120, {8, 7, 4, 1, 0, 1, 4, 7}]  Harvey P. Dale, May 20 2012

PROG

(PARI) {m=105; for(n=1, m, r=(n-1)%8; print1(if(r==0, 8, if(r==1||r==7, 7, if(r==2||r==6, 4, if(r==4, 0, 1)))), ", "))}

(MAGMA) m:=105; [ [8, 7, 4, 1, 0, 1, 4, 7][(n-1) mod 8 + 1]: n in [1..m] ];

CROSSREFS

Cf. A131074, A131028.

Sequence in context: A086253 A225119 A094883 * A158288 A193716 A268046

Adjacent sequences:  A131078 A131079 A131080 * A131082 A131083 A131084

KEYWORD

nonn,easy,less

AUTHOR

Klaus Brockhaus, following a suggestion of Paul Curtz, Jun 14 2007

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 December 13 15:03 EST 2018. Contains 318086 sequences. (Running on oeis4.)