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 A340989 #5 Feb 03 2021 23:20:28 %S A340989 2,4,7,9,18,21,24,29,32,49,51,55,60,62,72,85,92,95,104,107,110,118, %T A340989 127,135,146,164,166,169,176,179,202,205,218,220,232,237,247,262,265, %U A340989 279,287,290,303,306,309,313,328,339,347,350,355,363,366,399,403,412,418,424,433,441,443,456,476,479 %N A340989 The index of A337182 where prime(n) first appears as a factor. %C A340989 a(1) = 2 as A337182(2) = 2 which contains prime(1) = 2 as a factor. %C A340989 a(2) = 4 as A337182(4) = 6 which contains prime(2) = 3 as a factor. %C A340989 a(3) = 7 as A337182(7) = 10 which contains prime(3) = 5 as a factor. %C A340989 a(4) = 9 as A337182(9) = 14 which contains prime(4) = 7 as a factor. %Y A340989 Cf. A337182, A338222, A098550, A336957, A064413, A027746. %K A340989 nonn %O A340989 1,1 %A A340989 _Scott R. Shannon_, Feb 01 2021