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 A367624 #16 Dec 07 2023 08:27:58
%S A367624 1,2,2,1,1,3,1,3,1,2,2,1,4,1,4,1,1,2,1,2,1,3,1,2,3,1,2,1,1,5,1,2,5,1,
%T A367624 2,1,3,1,3,1,1,2,1,2,1,4,1,2,4,1,2,1,3,1,1,3,1,2,2,1,6,1,1,6,1,2,1,2,
%U A367624 1,3,3,1,2,1,1,2,1,4,1,4,1,2,1,3,2,1,3,1,2,1,5,1,2,1
%N A367624 2-adic valuation of A123581(2*n).
%C A367624 A123581(n) is odd if n is odd.
%H A367624 N. J. A. Sloane, <a href="/A367624/b367624.txt">Table of n, a(n) for n = 1..5000</a>
%t A367624 With[{nmax=100},IntegerExponent[NestList[#+FactorInteger[#][[-1,1]]&,3,2nmax-1][[2;;-1;;2]],2]] (* _Paolo Xausa_, Dec 07 2023 *)
%Y A367624 Cf. A007814, A123581.
%K A367624 nonn
%O A367624 1,2
%A A367624 _N. J. A. Sloane_, Dec 06 2023