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 A361104 #21 Mar 05 2023 20:51:02 %S A361104 1,2,3,17,9,4,8,31,15,7,5,47,64,6,21,10,96,20,11,13,57,38,14,16,79,37, %T A361104 18,12,160,28,22,19,61,24,26,23,131,52,27,25,41,33,46,29,77,45,42,34, %U A361104 54,59,36,32,68,72,44,40,104,82,50,49,75,111,51,35,98,143,63,30,85 %N A361104 a(n) = k such that A361103(k-1) = n, or -1 if n never appears in A361103. %C A361104 Imagine the offset of A361103 is 1, and assume it really is a permutation of the natural numbers. In tabular form, it is %C A361104 ..1..2..3..4..5..6..7..8..9.10.11... %C A361104 ..1..2..3..6.11.14.10..7..5.16..19... %C A361104 Then the inverse permutation would be %C A361104 ..1..2..3.17..9..4..8.31.15..7..5.47... %C A361104 which is the present sequence. %H A361104 N. J. A. Sloane, <a href="/A361104/b361104.txt">Table of n, a(n) for n = 1..2721</a> %e A361104 A361103(16) = 4, so a(4) = 17. %Y A361104 Cf. A360519, A361102, A336957, A361103. %K A361104 nonn %O A361104 1,2 %A A361104 _Scott R. Shannon_ and _N. J. A. Sloane_, Mar 02 2023 %E A361104 Edited by _N. J. A. Sloane_, Mar 04 2023