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 A352205 #17 Apr 26 2022 03:37:38 %S A352205 0,1,4,16,28,76,162,418,650,1892,3555,7252,20059,39786,84653,174566, %T A352205 343911,690189,1688099,3366971,7131089,14446268,31036955,62485240, %U A352205 145444358,290692248,624275567 %N A352205 a(0) = 0; for n>0, a(n) is the index of the last term in A109812 that is <= 2^n - 1. %C A352205 It appears that the last term in A109812 of binary length n is always 2^n - 1 itself. The term after that is (by definition) A352206(n). %C A352205 If we subtract 1 from a(n), we appear to get a subsequence of A352204, the indices of record high points in A109812. %C A352205 There are also occasional near-coincidences with A305370. %e A352205 The last term in A109812 of binary length at most 3 is A109812(16) = 7, so a(3) = 16. %Y A352205 Cf. A109812, A305370, A352203, A352204, A352206. %K A352205 nonn,base,more %O A352205 0,3 %A A352205 _N. J. A. Sloane_ and _Chai Wah Wu_, Mar 29 2022 %E A352205 a(18)-a(26) from _Walter Trump_, Apr 26 2022