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 A355170 #10 Jun 22 2022 21:32:15 %S A355170 4,6,8,9,10,12,15,16,14,18,20,21,24,25,28,30,27,32,35,36,22,40,42,33, %T A355170 45,48,49,26,44,50,54,56,39,55,60,63,64,52,66,70,72,65,77,80,81,34,78, %U A355170 84,88,90,51,75,91,96,99,100,38,68,98,104,108,110,57,85,105 %N A355170 The composite numbers in order of appearance in A173395. %C A355170 This sequence can be generated by removing duplicates from A173395. As such, every number in this sequence is composite, and every composite number appears in this sequence. %C A355170 This gives a method of enumerating the composite numbers. %e A355170 This sequence can be generated by reading along the diagonals of the multiplication table with headers starting at 2, skipping any number that has already been seen: %e A355170 4 6 8 10 12 ... %e A355170 6 9 12 15 18 ... %e A355170 8 12 16 20 24 ... %e A355170 10 15 20 25 30 ... %e A355170 12 18 24 30 36 ... %e A355170 ... %Y A355170 Cf. A173395, A257471 (similar construction). %K A355170 nonn,easy %O A355170 1,1 %A A355170 _Denver Massey_, Jun 22 2022