cp's OEIS Frontend

A248893 a(0)=0; for n>0, choose a(n) to be the smallest number > a(n-1) such that the condition a(n) > Sum_{k=0..n} (number of 1's in binary expansion of n a(k)) holds.

%I A248893 #11 Jul 23 2025 11:47:38
%S A248893 0,2,4,5,8,9,10,12,16,17,18,20,22,24,28,32,33,34,35,38,40,44,48,49,52,
%T A248893 56,58,64,65,66,67,68,72,73,76,80,81,84,88,92,96,97,100,104,106,112,
%U A248893 113,118,124,128,129,130,131,134,136,140,144,145,148,152,154,160
%N A248893 a(0)=0; for n>0, choose a(n) to be the smallest number > a(n-1) such that the condition a(n) > Sum_{k=0..n} (number of 1's in binary expansion of n a(k)) holds.
%C A248893 See A244510 for a decimal version.
%H A248893 Lars Blomberg, <a href="/A248893/b248893.txt">Table of n, a(n) for n = 0..10000</a>
%e A248893 a(7)=12 because the sum of 1's in the binary expansions of a(0)..a(6) is 9, and 12 is the smallest number greater than a(6)=10 and also greater than 9 + sum of 1's in the binary expansion of 12 (which is 2).
%Y A248893 Cf. A000120, A244510
%K A248893 nonn,base
%O A248893 0,2
%A A248893 _Lars Blomberg_, Mar 06 2015