login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

a(n) is the concatenation 1 written in base 2 once, 2 written in base 2 twice, ..., n written in base 2 n times.
3

%I #15 Mar 09 2018 06:05:49

%S 1,11010,11010111111,11010111111100100100100,

%T 11010111111100100100100101101101101101,

%U 11010111111100100100100101101101101101110110110110110110,11010111111100100100100101101101101101110110110110110110111111111111111111111

%N a(n) is the concatenation 1 written in base 2 once, 2 written in base 2 twice, ..., n written in base 2 n times.

%H Seiichi Manyama, <a href="/A300557/b300557.txt">Table of n, a(n) for n = 1..21</a>

%Y Cf. A007088, A098129, A300558.

%K nonn

%O 1,2

%A _Seiichi Manyama_, Mar 08 2018