A113215 - OEIS

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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

(list; graph; refs; listen; history; text; internal format)

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 ..]