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 A364969 #45 Dec 31 2023 00:50:05 %S A364969 1,1,2,1,3,2,2,1,4,1,5,3,2,1,6,2,5,3,3,2,6,2,7,2,8,1,7,2,9,4,2,1,8,1, %T A364969 9,4,3,2,11,5,3,2,12,3,7,2,13,2,14,1,10,1,11,5,4,1,12,3,8,1,13,2,15,6, %U A364969 3,2,16,2,17,5,5,3,10,1,14,1,15,6,4,1,16,2 %N A364969 a(n) = a(a(n-1)) if n is even, a(n) is the number of times a(n-1) occurs in the sequence so far if n is odd, with a(1) = 1. %C A364969 Conjecture: All positive integers appear in the sequence. %e A364969 a(1) = 1 (by definition). %e A364969 a(2) = a(a(1)) = a(1) = 1 (2 is even). %e A364969 a(3) = number of times a(2) occurs = number of times 1 occurs = 2 (3 is odd). %e A364969 a(4) = a(a(3)) = a(2) = 1 (4 is even). %e A364969 a(5) = number of times a(4) occurs = number of times 1 occurs = 3 (5 is odd). %e A364969 a(6) = a(a(5)) = a(3) = 2 (6 is even). %o A364969 (PARI) lista(nn) = my(va = vector(nn)); va[1] = 1; for (n=2, nn, if (n%2, va[n] = #select(x->(x==va[n-1]), va), va[n] = va[va[n-1]]);); va; \\ _Michel Marcus_, Oct 23 2023 %K A364969 nonn %O A364969 1,3 %A A364969 _Tanmaya Mohanty_, Oct 23 2023