OFFSET
1,1
FORMULA
a(n)=n+Floor[1/2+(2n/7)^(1/2)].
MATHEMATICA
Table[n+Floor[1/2+(2n/7)^(1/2)], {n, 100}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 01 2011
STATUS
approved