A079073 Sum of numbers < n having in binary representation the same number of 1's as n.

0, 0, 1, 0, 3, 3, 8, 0, 7, 14, 23, 7, 33, 18, 31, 0, 15, 45, 62, 45, 80, 64, 85, 15, 100, 107, 132, 38, 158, 65, 94, 0, 31, 124, 157, 186, 191, 221, 258, 124, 227, 296, 337, 163, 379, 206, 251, 31, 267, 423, 472, 297, 522, 348, 401, 78, 574, 455, 512, 133, 570, 192, 253, 0, 63

Offset: 0

Author

Reinhard Zumkeller, Dec 21 2002

Keywords

• nonn
• look
• base

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..16383

Crossrefs

Cf. A079072, A079074, A068076, A007088, A000120.

Programs

Maple

f:= n-> add(i, i=convert(n, base, 2)):
b:= proc(n) b(n):= b(n-1)+n*x^f(n) end: b(-1):=0:
a:= n-> coeff(b(n-1), x, f(n)):
seq(a(n), n=0..150);  # Alois P. Heinz, Feb 08 2018

Mathematica

a[n_] := Module[{dc = DigitCount[n, 2, 1]}, Select[Range[n-1], DigitCount[#, 2, 1] == dc&] // Total];
a /@ Range[0, 100] (* Jean-François Alcover, Nov 07 2020 *)

PARI

a(n) = my(s=hammingweight(n)); sum(k=1, n-1, if (s==hammingweight(k), k)); \\ Michel Marcus, Nov 07 2020