OFFSET
1,1
FORMULA
a(n) = n + ceiling(n^2/25).
MATHEMATICA
a=25; b=-25;
Table[n+Floor[(a*n+b)^(1/2)], {n, 100}]
Table[n-1+Ceiling[(n^2-b)/a], {n, 90}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jan 09 2011
STATUS
approved