A246867 Triangle T(n,k) in which n-th row lists in increasing order all partitions lambda of n into distinct parts encoded as Product_{i:lambda} prime(i); n>=0, 1<=k<=A000009(n).
1, 2, 3, 5, 6, 7, 10, 11, 14, 15, 13, 21, 22, 30, 17, 26, 33, 35, 42, 19, 34, 39, 55, 66, 70, 23, 38, 51, 65, 77, 78, 105, 110, 29, 46, 57, 85, 91, 102, 130, 154, 165, 210, 31, 58, 69, 95, 114, 119, 143, 170, 182, 195, 231, 330, 37, 62, 87, 115, 133, 138, 187
Offset: 0
Examples
The partitions of n=5 into distinct parts are {[5], [4,1], [3,2]}, encodings give {prime(5), prime(4)*prime(1), prime(3)*prime(2)} = {11, 7*2, 5*3} => row 5 = [11, 14, 15]. For n=0 the empty partition [] gives the empty product 1. Triangle T(n,k) begins: 1; 2; 3; 5, 6; 7, 10; 11, 14, 15; 13, 21, 22, 30; 17, 26, 33, 35, 42; 19, 34, 39, 55, 66, 70; 23, 38, 51, 65, 77, 78, 105, 110; 29, 46, 57, 85, 91, 102, 130, 154, 165, 210; ... Corresponding triangle of strict integer partitions begins: 0 (1) (2) (3) (21) (4) (31) (5) (41) (32) (6) (42) (51) (321) (7) (61) (52) (43) (421) (8) (71) (62) (53) (521) (431) (9) (81) (72) (63) (54) (621) (432) (531). - _Gus Wiseman_, Feb 23 2018
Links
- Alois P. Heinz, Rows n = 0..42, flattened
Crossrefs
Programs
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Maple
b:= proc(n, i) option remember; `if`(n=0, [1], `if`(i<1, [], [seq( map(p->p*ithprime(i)^j, b(n-i*j, i-1))[], j=0..min(1, n/i))])) end: T:= n-> sort(b(n$2))[]: seq(T(n), n=0..14);
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Mathematica
b[n_, i_] := b[n, i] = If[n==0, {1}, If[i<1, {}, Flatten[Table[Map[ #*Prime[i]^j&, b[n-i*j, i-1]], {j, 0, Min[1, n/i]}]]]]; T[n_] := Sort[b[n, n]]; Table[T[n], {n, 0, 14}] // Flatten (* Jean-François Alcover, Dec 18 2016, after Alois P. Heinz *)
Comments