A320796 Regular triangle where T(n,k) is the number of non-isomorphic self-dual multiset partitions of weight n with k parts.
1, 1, 1, 1, 2, 1, 1, 4, 3, 1, 1, 5, 7, 3, 1, 1, 7, 14, 10, 3, 1, 1, 9, 23, 24, 11, 3, 1, 1, 12, 39, 53, 34, 12, 3, 1, 1, 14, 61, 102, 86, 39, 12, 3, 1, 1, 17, 90, 193, 201, 117, 42, 12, 3, 1, 1, 20, 129, 340, 434, 310, 136, 43, 12, 3, 1, 1, 24, 184, 584, 902, 778, 412, 149, 44, 12, 3, 1
Offset: 1
Examples
Triangle begins: 1 1 1 1 2 1 1 4 3 1 1 5 7 3 1 1 7 14 10 3 1 1 9 23 24 11 3 1 1 12 39 53 34 12 3 1 1 14 61 102 86 39 12 3 1 1 17 90 193 201 117 42 12 3 1 Non-isomorphic representatives of the multiset partitions for n = 1 through 5 (commas elided): 1: {{1}} . 2: {{11}} {{1}{2}} . 3: {{111}} {{1}{22}} {{1}{2}{3}} . {{2}{12}} . 4: {{1111}} {{11}{22}} {{1}{1}{23}} {{1}{2}{3}{4}} . {{12}{12}} {{1}{2}{33}} . {{1}{222}} {{1}{3}{23}} . {{2}{122}} . 5: {{11111}} {{11}{122}} {{1}{22}{33}} {{1}{2}{2}{34}} {{1}{2}{3}{4}{5}} . {{11}{222}} {{1}{23}{23}} {{1}{2}{3}{44}} . {{12}{122}} {{1}{2}{333}} {{1}{2}{4}{34}} . {{1}{2222}} {{1}{3}{233}} . {{2}{1222}} {{2}{12}{33}} . {{2}{13}{23}} . {{3}{3}{123}}
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..1275 (rows 1..50)
Crossrefs
Programs
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PARI
row(n)={vector(n, k, T(k,n) - T(k-1,n))} \\ T(n,k) defined in A318805. - Andrew Howroyd, Jan 16 2024
Formula
Extensions
a(56) onwards from Andrew Howroyd, Jan 16 2024
Comments