0,3

The sequence appears to have a peak-like (von Koch?) self-similar structure.

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

a(0)=0;a(1)=a(2)=1; a(n)=a(n-a(n-1))+a(Floor[n/2]]

f[0] = 0; f[1] = 1; f[1] = 1; f[n_] := f[n] = f[n - f[n - 1]] + f[Floor[n/2]]; b = Table[f[n], {n, 0, 200}]

(Haskell)

a140472 n = a140472_list !! n

a140472_list = 0 : 1 : h 2 1 where

h x y = z : h (x + 1) z where z = a140472 (x - y) + a140472 (x `div` 2)

-- Reinhard Zumkeller, Jul 20 2012

Cf. A004001.

Cf. A214546 (first differences).

Sequence in context: A117484 A086835 A046701 * A109168 A015134 A171580

Adjacent sequences: A140469 A140470 A140471 * A140473 A140474 A140475

nonn

Roger L. Bagula and Gary W. Adamson, Jun 28 2008

Offset corrected by Reinhard Zumkeller, Jul 20 2012

approved