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 A228350 #35 Oct 22 2013 12:38:18 %S A228350 1,2,1,1,3,2,1,1,1,2,1,1,4,3,2,2,1,1,1,1,1,2,1,1,3,2,1,1,1,2,1,1,5,4, %T A228350 3,3,2,2,2,2,1,1,1,1,1,1,1,1,1,2,1,1,3,2,1,1,1,2,1,1,4,3,2,2,1,1,1,1, %U A228350 1,2,1,1,3,2,1,1,1,2,1,1,6,5,4,4,3,3 %N A228350 Triangle read by rows: T(j,k) is the k-th part in nonincreasing order of the j-th region of the set of compositions (ordered partitions) of n in colexicographic order, if 1<=j<=2^(n-1) and 1<=k<=A006519(j). %C A228350 Triangle read by rows in which row n lists the A006519(n) elements of the row A001511(n) of triangle A065120, n >= 1. %C A228350 The equivalent sequence for integer partitions is A206437. %F A228350 T(j,k) = A065120(A001511(j)),k) = A001511(j) - A029837(k), 1<=k<=A006519(j), j>=1. %e A228350 --------------------------------------------------------- %e A228350 . Diagram Triangle %e A228350 Compositions of of compositions (rows) %e A228350 . of 5 regions and regions (columns) %e A228350 ---------------------------------------------------------- %e A228350 . _ _ _ _ _ %e A228350 . 5 |_ | 5 %e A228350 . 1+4 |_|_ | 1 4 %e A228350 . 2+3 |_ | | 2 3 %e A228350 . 1+1+3 |_|_|_ | 1 1 3 %e A228350 . 3+2 |_ | | 3 2 %e A228350 . 1+2+2 |_|_ | | 1 2 2 %e A228350 . 2+1+2 |_ | | | 2 1 2 %e A228350 . 1+1+1+2 |_|_|_|_ | 1 1 1 2 %e A228350 . 4+1 |_ | | 4 1 %e A228350 . 1+3+1 |_|_ | | 1 3 1 %e A228350 . 2+2+1 |_ | | | 2 2 1 %e A228350 . 1+1+2+1 |_|_|_ | | 1 1 2 1 %e A228350 . 3+1+1 |_ | | | 3 1 1 %e A228350 . 1+2+1+1 |_|_ | | | 1 2 1 1 %e A228350 . 2+1+1+1 |_ | | | | 2 1 1 1 %e A228350 . 1+1+1+1+1 |_|_|_|_|_| 1 1 1 1 1 %e A228350 . %e A228350 Also the structure could be represented by an isosceles triangle in which the n-th diagonal gives the n-th region. For the composition of 4 see below: %e A228350 . _ _ _ _ %e A228350 . 4 |_ | 4 %e A228350 . 1+3 |_|_ | 1 3 %e A228350 . 2+2 |_ | | 2 2 %e A228350 . 1+1+2 |_|_|_ | 1 1 2 %e A228350 . 3+1 |_ | | 3 1 %e A228350 . 1+2+1 |_|_ | | 1 2 1 %e A228350 . 2+1+1 |_ | | | 2 1 1 %e A228350 . 1+1+1+1 |_|_|_|_| 1 1 1 1 %e A228350 . %e A228350 Illustration of the four sections of the set of compositions of 4: %e A228350 . _ _ _ _ %e A228350 . |_ | 4 %e A228350 . |_|_ | 1+3 %e A228350 . |_ | | 2+2 %e A228350 . _ _ _ |_|_|_ | 1+1+2 %e A228350 . |_ | 3 | | 1 %e A228350 . _ _ |_|_ | 1+2 | | 1 %e A228350 . _ |_ | 2 | | 1 | | 1 %e A228350 . |_| 1 |_| 1 |_| 1 |_| 1 %e A228350 . %e A228350 . %e A228350 Illustration of initial terms. The parts of the eight regions of the set of compositions of 4: %e A228350 -------------------------------------------------------- %e A228350 \j: 1 2 3 4 5 6 7 8 %e A228350 k %e A228350 -------------------------------------------------------- %e A228350 . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ %e A228350 1 |_|1 |_ |2 |_|1 |_ |3 |_|1 |_ |2 |_|1 |_ |4 %e A228350 2 |_|1 |_ |2 |_|1 |_ |3 %e A228350 3 | |1 | |2 %e A228350 4 |_|1 |_ |2 %e A228350 5 | |1 %e A228350 6 | |1 %e A228350 7 | |1 %e A228350 8 |_|1 %e A228350 . %e A228350 Triangle begins: %e A228350 1; %e A228350 2,1; %e A228350 1; %e A228350 3,2,1,1; %e A228350 1; %e A228350 2,1; %e A228350 1; %e A228350 4,3,2,2,1,1,1,1; %e A228350 1; %e A228350 2,1; %e A228350 1; %e A228350 3,2,1,1; %e A228350 1; %e A228350 2,1; %e A228350 1; %e A228350 5,4,3,3,2,2,2,2,1,1,1,1,1,1,1,1; %e A228350 ... %e A228350 . %e A228350 Also triangle read by rows T(n,m) in which row n lists the parts of the n-th section of the set of compositions of the integers >= n, ordered by regions. Row lengths give A045623. Row sums give A001792 (see below): %e A228350 [1]; %e A228350 [2,1]; %e A228350 [1],[3,2,1,1]; %e A228350 [1],[2,1],[1],[4,3,2,2,1,1,1,1]; %e A228350 [1],[2,1],[1],[3,2,1,1],[1],[2,1],[1],[5,4,3,3,2,2,2,2,1,1,1,1,1,1,1,1]; %Y A228350 Main triangle: column 1 is A001511. Row j has length A006519(j). Row sums give A038712. %Y A228350 Cf. A001787, A001792, A011782, A029837, A045623, A065120, A070939, A135010, A141285, A187816, A187818, A193870, A206437, A228347, A228348, A228349, A228351, A228366, A228367, A228370, A228371, A228525, A228526. %K A228350 nonn,tabf %O A228350 1,2 %A A228350 _Omar E. Pol_, Aug 20 2013