OFFSET
1,1
COMMENTS
See A184117 for the definition of lower and upper s-Wythoff sequences.
MATHEMATICA
mex:=First[Complement[Range[1, Max[#1]+1], #1]]&;
s[n_]:=n (n+1)/2; a[1]=1; b[n_]:=b[n]=s[n]+a[n];
a[n_]:=a[n]=mex[Flatten[Table[{a[i], b[i]}, {i, 1, n-1}]]];
Table[s[n], {n, 40}]
Table[a[n], {n, 120}]
Table[b[n], {n, 100}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 14 2011
STATUS
approved