OFFSET
1,2
COMMENTS
FORMULA
a(n)=floor[n*(-1+sqrt(13))/2].
b(n)=floor[n*(5+sqrt(13))/2]=A001956(n).
MATHEMATICA
k=3; r=0; d=Sqrt[4+k^2];
a[n_]:=Floor[(1/2)(d+2-k)(n+r/(d+2))];
b[n_]:=Floor[(1/2)(d+2+k)(n-r/(d+2))];
Table[a[n], {n, 120}]
Table[b[n], {n, 120}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 15 2011
STATUS
approved