OFFSET
1,1
FORMULA
a(n)=n+Floor[sqrt(2n+2)].
MATHEMATICA
a=2; b=2; Table[n+Floor[(a*n+b)^(1/2)], {n, 80}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jan 05 2011
STATUS
approved