login
A285194
Expansion of (1+x^2)/(1+x+x^4) mod 3.
1
1, 2, 2, 1, 1, 0, 1, 1, 1, 2, 0, 2, 0, 1, 2, 2, 1, 1, 0, 1, 1, 1, 2, 0, 2, 0, 1, 2, 2, 1, 1, 0, 1, 1, 1, 2, 0, 2, 0, 1, 2, 2, 1, 1, 0, 1, 1, 1, 2, 0, 2, 0, 1, 2, 2, 1, 1, 0, 1, 1, 1, 2, 0, 2, 0, 1, 2, 2, 1, 1, 0, 1, 1, 1, 2, 0, 2, 0
OFFSET
0,2
COMMENTS
Periodic with period (1, 2, 2, 1, 1, 0, 1, 1, 1, 2, 0, 2, 0).
REFERENCES
Arthur Gill, Linear Sequential Circuits, McGraw-Hill, 1966, Eq. (17-11).
FORMULA
From Colin Barker, Apr 27 2017: (Start)
G.f.: (2*x^11 + 2*x^9 + x^8 + x^7 + x^6 + x^4 + x^3 + 2*x^2 + 2*x + 1)/(1 - x^13).
a(n) = a(n-13) for n>12.
(End)
MAPLE
t5:=(1+x^2)/(1+x+x^4);
t6:=series(%, x, 120):
t7:=seriestolist(%);
t8:=% mod 3;
PROG
(PARI) Vec((2*x^11 + 2*x^9 + x^8 + x^7 + x^6 + x^4 + x^3 + 2*x^2 + 2*x + 1)/(1 - x^13) + O(x^100)) \\ Colin Barker, Apr 27 2017
CROSSREFS
Sequence in context: A328698 A359936 A317529 * A039978 A099918 A099860
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Apr 26 2017
STATUS
approved