A131079 Periodic sequence (2, 2, 2, 1, 0, 0, 0, 1).

2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2

Offset

1,1

Comments

Second 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(n) = a(n-8).

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

Mathematica

PadRight[{}, 120, {2, 2, 2, 1, 0, 0, 0, 1}] (* Harvey P. Dale, Mar 04 2020 *)

Prog

(PARI) {m=105; for(n=1, m, r=(n-1)%8; print1(if(r<3, 2, if(r==3||r==7, 1, 0)), ", "))}
(Magma) m:=105; [ [2, 2, 2, 1, 0, 0, 0, 1][(n-1) mod 8 + 1]: n in [1..m] ];

Crossrefs

Cf. A131074, A131026.

Sequence in context: A390108 A392180 A292520 * A334889 A078336 A076441

Adjacent sequences: A131076 A131077 A131078 * A131080 A131081 A131082

Keyword

nonn,easy,less

Author

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

Status

approved