0,5

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

a(n)=sum{k=0..n, floor(sqrt(n)/(k+1))}.

(Haskell)

a113215 n = a113215_list !! n

a113215_list = concat $ zipWith take

[1, 3 ..] $ map (repeat . a006218) [0 ..]

-- Reinhard Zumkeller, May 30 2015

Cf. A006218.

Sequence in context: A112593 A213809 A204854 * A105591 A130497 A178154

Adjacent sequences: A113212 A113213 A113214 * A113216 A113217 A113218

easy,nonn

Paul Barry, Oct 18 2005

approved