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 A330897 #14 May 03 2020 15:31:27 %S A330897 1,3,8,12,21,35,43,71,85,107,133,138,173,220,240,290,320,355,405,430, %T A330897 512,559,593,622,727,731,846,901,940,1071,1107,1207,1279,1389,1490, %U A330897 1544,1657,1699,1768,1870,1935,2049,2198,2346,2468,2478,2612,2693,2817,2919 %N A330897 a(n) is the least k such that A330896(k) = n. %H A330897 Rémy Sigrist, <a href="/A330897/b330897.txt">Table of n, a(n) for n = 1..10000</a> %H A330897 Rémy Sigrist, <a href="/A330897/a330897.txt">C program for A330897</a> %F A330897 A330896(a(n)) = n. %e A330897 The first terms of A330896 are: %e A330897 n| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 ... %e A330897 A330896(n)| 1 1 2 1 2 2 1 3 2 3 1 4 2 3 3 1 4 2 4 3 5 ... %e A330897 - hence a(1) = 1, a(2) = 3, a(3) = 8, a(4) = 12, a(5) = 21. %o A330897 (C) See Links section. %Y A330897 Cf. A330896. %K A330897 nonn %O A330897 1,2 %A A330897 _Rémy Sigrist_, May 01 2020