OFFSET
1,1
FORMULA
a(n) = n + floor(4*sqrt(n+1))
MATHEMATICA
a=16; b=16; Table[n+Floor[(a*n+b)^(1/2)], {n, 100}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jan 09 2011
STATUS
approved