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 A327469 #9 Jul 09 2025 04:49:05 %S A327469 0,0,0,1,1,1,1,1,3,3,3,4,4,4,4,5,5,7,7,8,8,8,8,8,12,12,12,13,13,13,13, %T A327469 14,14,14,14,19,19,19,19,19,19,19,19,20,22,22,22,23,29,33,33,34,34,34, %U A327469 34,34,34,34,34,35,35,35,37,40,40,40,40,41,41,41,41,45,45,45,49,50,50,50,50,51,55,55,55,56,56,56,56,56,56,58,58,59,59,59,59,60,60,66,68,77 %N A327469 Number of nonempty subsets of [1..n] which are geometric progressions of length >= 3 with rational ratio and are locally maximal. %C A327469 Exceptionally, DATA section give first 100 terms. %C A327469 One might have expected that the GP would be required to have an integer ratio, but in fact we allow rational ratios. The GPs can be assumed to be increasing. %Y A327469 Cf. A309095, A327466. %K A327469 nonn %O A327469 1,9 %A A327469 _N. J. A. Sloane_, Oct 03 2019, using data computed by _Rob Pratt_