OFFSET
0
LINKS
Michael R. Bush and Danjoseph Quijada, Period sets of linear recurrence over finite fields and related commutative rings, arXiv:1805.03238 [math.NT], 2018 (see Remark 3.7, page 13).
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1).
FORMULA
G.f.: x^4*(1+x+x^2+x^3+x^4+x^6+x^8+x^11+x^12+x^16)/(1-x^21).
a(n) = a(n-21) for n >= 21.
MATHEMATICA
CoefficientList[Series[(x^4 (1 + x + x^2 + x^3 + x^4 + x^6 + x^8 + x^11 + x^12 + x^16))/(1 - x^21), {x, 0, 100}], x]
PadRight[{}, 120, {0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1}] (* Harvey P. Dale, Oct 13 2020 *)
PROG
(Magma) &cat[[0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1]^^4];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, May 15 2018
STATUS
approved