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 A220659 #17 Mar 31 2025 23:10:31 %S A220659 0,0,1,0,1,2,0,1,2,0,1,2,0,1,2,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2, %T A220659 3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0, %U A220659 1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3 %N A220659 Irregular table: row n (n >= 1) consists of numbers 0..A084558(n). %C A220659 The term a(n) gives the position (zero-based, starting from the left hand end of permutation) of a corresponding permutation A055089 and A060117/A060118 from which the term A055089(n) or A060118(n) is to be picked. %H A220659 Antti Karttunen, <a href="/A220659/b220659.txt">Rows 0..720 of the irregular table, flattened.</a> %F A220659 a(n) = n - A220657(A220658(n)). %e A220659 Rows of this irregular table begin as: %e A220659 0; %e A220659 0, 1; %e A220659 0, 1, 2; %e A220659 0, 1, 2; %e A220659 0, 1, 2; %e A220659 0, 1, 2; %e A220659 0, 1, 2, 3; %e A220659 The term 2 occurs four times in A084558, in positions 2, 3, 4 and 5. Thus rows 2, 3, 4 and 5 (zero-based) of this irregular table are all 0,1,2. %o A220659 (Scheme) (define (A220659 n) (- n (A220657 (A220658 n)))) %K A220659 nonn,tabf %O A220659 0,6 %A A220659 _Antti Karttunen_, Dec 18 2012