A113215 Repeat A006218(n) 2n+1 times.

0, 1, 1, 1, 3, 3, 3, 3, 3, 5, 5, 5, 5, 5, 5, 5, 8, 8, 8, 8, 8, 8, 8, 8, 8, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20

Offset

0,5

Links

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

Formula

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

Prog

(Haskell)
a113215 n = a113215_list !! n
a113215_list = concat $ zipWith take
                        [1, 3 ..] $ map (repeat . a006218) [0 ..]
-- Reinhard Zumkeller, May 30 2015

Crossrefs

Cf. A006218.

Sequence in context: A112593 A213809 A204854 * A105591 A130497 A178154

Adjacent sequences: A113212 A113213 A113214 * A113216 A113217 A113218

Keyword

easy,nonn

Author

Paul Barry, Oct 18 2005

Status

approved