A325280 Triangle read by rows where T(n,k) is the number of integer partitions of n with adjusted frequency depth k.
1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 2, 1, 1, 0, 1, 1, 2, 3, 0, 0, 1, 3, 4, 3, 0, 0, 0, 1, 1, 4, 8, 1, 0, 0, 0, 1, 3, 6, 9, 3, 0, 0, 0, 0, 1, 2, 8, 12, 7, 0, 0, 0, 0, 0, 1, 3, 11, 17, 10, 0, 0, 0, 0, 0, 0, 1, 1, 11, 26, 17, 0, 0, 0, 0, 0, 0, 0, 1, 5, 19, 25, 27
Offset: 0
Examples
Triangle begins: 1 0 1 0 1 1 0 1 1 1 0 1 2 1 1 0 1 1 2 3 0 0 1 3 4 3 0 0 0 1 1 4 8 1 0 0 0 1 3 6 9 3 0 0 0 0 1 2 8 12 7 0 0 0 0 0 1 3 11 17 10 0 0 0 0 0 0 1 1 11 26 17 0 0 0 0 0 0 0 1 5 19 25 27 0 0 0 0 0 0 0 0 1 1 17 44 38 0 0 0 0 0 0 0 0 0 1 3 25 53 52 1 0 0 0 0 0 0 0 0 0 1 3 29 63 76 4 0 0 0 0 0 0 0 0 0 0 1 4 37 83 98 8 0 0 0 0 0 0 0 0 0 0 Row n = 9 counts the following partitions: (9) (333) (54) (441) (3321) (111111111) (63) (522) (4221) (72) (711) (4311) (81) (3222) (5211) (432) (6111) (32211) (531) (22221) (42111) (621) (33111) (321111) (222111) (51111) (411111) (2211111) (3111111) (21111111)
Links
- Andrew Howroyd, Table of n, a(n) for n = 0..1325 (rows 0..50)
Crossrefs
Programs
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Mathematica
fdadj[ptn_List]:=If[ptn=={},0,Length[NestWhileList[Sort[Length/@Split[#]]&,ptn,Length[#]>1&]]]; Table[Length[Select[IntegerPartitions[n],fdadj[#]==k&]],{n,0,16},{k,0,n}]
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PARI
\\ depth(p) gives adjusted frequency depth of partition. depth(p)={if(!#p, 0, my(r=1); while(#p > 1, my(L=List(), k=0); for(i=1, #p, if(i==#p||p[i]<>p[i+1], listput(L,i-k); k=i)); listsort(L); p=L; r++); r)} row(n)={my(v=vector(1+n)); forpart(p=n, v[1+depth(Vec(p))]++); v} { for(n=0, 10, print(row(n))) } \\ Andrew Howroyd, Jan 18 2023
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