OFFSET
1,2
FORMULA
a(n)=1+floor(2*n^2/3).
a(n) = 1 +A030511(n+1). - R. J. Mathar, Aug 25 2011
MATHEMATICA
c[k_]:=1+Floor[(2/3)k^2]; c=Table[c[k], {k, 1, 90}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Aug 14 2011
STATUS
approved