A249041 Number of odd terms in first n terms of A249039.

1, 1, 1, 2, 3, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 7, 8, 8, 9, 10, 11, 12, 13, 13, 14, 15, 16, 16, 17, 17, 17, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 23, 23, 23, 24, 25, 25, 26, 26, 26, 26, 27, 27, 27, 28, 29, 29, 30, 31, 32, 32, 33, 33, 33, 34, 35, 35, 36

Offset: 1

Author

N. J. A. Sloane, Oct 26 2014

Keywords

• nonn

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, Colored scatterplot of (a(n-1-a(n-1))/n, a(a(n-1))/n) for n <= 500000000 (where the hue is function of n)

Crossrefs

Cf. A249039, A249040, A287422.

Programs

Haskell

a249041 n = a249041_list !! (n-1)
a249041_list = tail $ scanl (\i j -> i + mod j 2) 0 a249039_list
-- Reinhard Zumkeller, Nov 11 2014

Maple

See A249039.

Formula

For n > 2: a(n) = a(n-1) + A249039(n) mod 2. - Reinhard Zumkeller, Nov 11 2014

a(n) = n - a(a(n-1)) - a(n-1-a(n-1)) with a(1) = a(2) = 1. - Altug Alkan, May 01 2019