This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A355483 #15 Feb 03 2024 10:14:25 %S A355483 1,2,3,5,6,15,23,9,7,10,27,29,12,63,95,30,255,383,17,18,111,39,43,20, %T A355483 119,45,123,46,51,53,24,447,54,479,33,57,58,60,4095,16777215, %U A355483 79228162514264337593543950335 %N A355483 a(1) = 1; for n > 1, a(n) is the smallest positive number that has not yet appeared such that the number of 1-bits in the binary expansion of a(n) equals the number of divisors of a(n-1). %C A355483 This sequence is similar to A355482 except that here all divisors of a(n-1) are counted. %C A355483 The fixed points in the first 41 terms are 1,2,3,10. %C A355483 It is unknown if all numbers eventually appear. %C A355483 Since a(41) has 6144 divisors, a(42) = 2^6144 - 1 is a 1850-digit number. %e A355483 a(7) = 23 = 10111_2 as a(6) = 15 which has four divisors, and 23 is the smallest unused number that has four 1-bits in its binary expansion. %Y A355483 Cf. A355482 (proper divisors), A355374, A000120, A032741, A005179, A027751. %K A355483 nonn,base %O A355483 1,2 %A A355483 _Scott R. Shannon_, Jul 03 2022