OFFSET
1,1
LINKS
P. Y. Huang, W. F. Ke, and G. F. Pilz, The cardinality of some symmetric differences, Proc. Amer. Math. Soc., 138 (2010), 787-797.
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,0,0,0,1,-1).
FORMULA
G.f.: 4*x*(x^10+x^6+x^5+x^4+1)/(x^13-x^12-x+1). - Alois P. Heinz, May 17 2023
MATHEMATICA
delta[l_, m_] := Complement[Join[l, m], Intersection[l, m]];
Nabl[s_, n_] := (d = {}; Do[d = delta[d, s*j], {j, Range[n]}]; d);
Table[Length[Nabl[Range[1, 4], n]], {n, 100}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Guenter Pilz, May 17 2023
STATUS
approved