cp's OEIS Frontend

A300557 a(n) is the concatenation 1 written in base 2 once, 2 written in base 2 twice, ..., n written in base 2 n times.

%I A300557 #15 Mar 09 2018 06:05:49
%S A300557 1,11010,11010111111,11010111111100100100100,
%T A300557 11010111111100100100100101101101101101,
%U A300557 11010111111100100100100101101101101101110110110110110110,11010111111100100100100101101101101101110110110110110110111111111111111111111
%N A300557 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 A300557 Seiichi Manyama, <a href="/A300557/b300557.txt">Table of n, a(n) for n = 1..21</a>
%Y A300557 Cf. A007088, A098129, A300558.
%K A300557 nonn
%O A300557 1,2
%A A300557 _Seiichi Manyama_, Mar 08 2018