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

0,4

Links

Table of n, a(n) for n=0..19.

Prog

(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

Crossrefs

Cf. A068943.

Sequence in context: A208202 A206482 A164582 * A219698 A293251 A061912

Adjacent sequences: A068942 A068943 A068944 * A068946 A068947 A068948

Keyword

base,more,nonn

Author

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

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

Status

approved