A068945 Number of ones in the binary expansion of A068943(n).

1, 1, 1, 2, 3, 13, 63, 199, 805, 3155, 12319, 48070, 186944, 727997, 2846645, 11109160, 43432775, 169958492, 665601661, 2608395091

Offset: 0

Author

Francois Jooste (phukraut(AT)hotmail.com), Mar 09 2002

Keywords

• base
• more
• nonn

Crossrefs

Cf. A068943.

Programs

Python

from gmpy2 import popcount
from math import comb, prod
def a(n):
    return popcount(prod((n-m+1)**comb(m+n-2, m-1) for m in range(1, n+1)))
print([a(n) for n in range(16)]) # Michael S. Branicky, Apr 09 2023

Extensions

a(13)-a(17) from Sean A. Irvine, Feb 24 2011

a(0) changed to 1 and a(18)-a(19) from Michael S. Branicky, Apr 09 2023