A305936
Irregular triangle whose n-th row is the multiset spanning an initial interval of positive integers with multiplicities equal to the n-th row of A296150 (the prime indices of n in weakly decreasing order).
Original entry on oeis.org
1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 3, 1, 1, 2, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 2, 3, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 1, 1, 1, 1, 2, 2, 1
Offset: 1
Row 90 is {1,1,1,2,2,3,3,4} because 90 = prime(3)*prime(2)*prime(2)*prime(1).
Triangle begins:
1:
2: 1
3: 1 1
4: 1 2
5: 1 1 1
6: 1 1 2
7: 1 1 1 1
8: 1 2 3
9: 1 1 2 2
10: 1 1 1 2
11: 1 1 1 1 1
12: 1 1 2 3
13: 1 1 1 1 1 1
Row lengths are
A056239. Number of distinct elements in row n is
A001222(n). Number of distinct multiplicities in row n is
A001221(n).
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nrmptn[n_]:=Join@@MapIndexed[Table[#2[[1]],{#1}]&,If[n==1,{},Flatten[Cases[FactorInteger[n]//Reverse,{p_,k_}:>Table[PrimePi[p],{k}]]]]];
Array[nrmptn,30]
A318361
Number of strict set multipartitions (sets of sets) of a multiset whose multiplicities are the prime indices of n.
Original entry on oeis.org
1, 1, 0, 2, 0, 1, 0, 5, 1, 0, 0, 4, 0, 0, 0, 15, 0, 5, 0, 1, 0, 0, 0, 16, 0, 0, 8, 0, 0, 2, 0, 52, 0, 0, 0, 23, 0, 0, 0, 7, 0, 0, 0, 0, 5, 0, 0, 68, 0, 1, 0, 0, 0, 40, 0, 1, 0, 0, 0, 14, 0, 0, 1, 203, 0, 0, 0, 0, 0, 0, 0, 111, 0, 0, 4, 0, 0, 0, 0, 41, 80, 0, 0
Offset: 1
The a(24) = 16 sets of sets with multiset union {1,1,2,3,4}:
{{1},{1,2,3,4}}
{{1,2},{1,3,4}}
{{1,3},{1,2,4}}
{{1,4},{1,2,3}}
{{1},{2},{1,3,4}}
{{1},{3},{1,2,4}}
{{1},{4},{1,2,3}}
{{1},{1,2},{3,4}}
{{1},{1,3},{2,4}}
{{1},{1,4},{2,3}}
{{2},{1,3},{1,4}}
{{3},{1,2},{1,4}}
{{4},{1,2},{1,3}}
{{1},{2},{3},{1,4}}
{{1},{2},{4},{1,3}}
{{1},{3},{4},{1,2}}
-
nrmptn[n_]:=Join@@MapIndexed[Table[#2[[1]],{#1}]&,If[n==1,{},Flatten[Cases[FactorInteger[n]//Reverse,{p_,k_}:>Table[PrimePi[p],{k}]]]]];
sqfacs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[sqfacs[n/d],Min@@#>d&]],{d,Select[Rest[Divisors[n]],SquareFreeQ]}]];
Table[Length[sqfacs[Times@@Prime/@nrmptn[n]]],{n,90}]
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permcount(v) = {my(m=1, s=0, k=0, t); for(i=1, #v, t=v[i]; k=if(i>1&&t==v[i-1], k+1, 1); m*=t*k; s+=t); s!/m}
sig(n)={my(f=factor(n)); concat(vector(#f~, i, vector(f[i, 2], j, primepi(f[i, 1]))))}
count(sig)={my(r=0, A=O(x*x^vecmax(sig))); for(n=1, vecsum(sig)+1, my(s=0); forpart(p=n, my(q=prod(i=1, #p, 1 + x^p[i] + A)); s+=prod(i=1, #sig, polcoef(q, sig[i]))*(-1)^#p*permcount(p)); r+=(-1)^n*s/n!); r/2}
a(n)={if(n==1, 1, my(s=sig(n)); if(#s==1, s[1]==1, count(sig(n))))} \\ Andrew Howroyd, Dec 18 2018
A318286
Number of strict multiset partitions of a multiset whose multiplicities are the prime indices of n.
Original entry on oeis.org
1, 1, 1, 2, 2, 3, 2, 5, 5, 5, 3, 9, 4, 7, 9, 15, 5, 18, 6, 16, 14, 10, 8, 31, 17, 14, 40, 25, 10, 34, 12, 52, 21, 19, 27, 70, 15, 25, 31, 59, 18, 57, 22, 38, 80, 33, 27, 120, 46, 67, 44, 56, 32, 172, 42, 100, 61, 43, 38, 141, 46, 55, 143, 203, 64, 91, 54, 80
Offset: 1
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nrmptn[n_]:=Join@@MapIndexed[Table[#2[[1]],{#1}]&,If[n==1,{},Flatten[Cases[FactorInteger[n]//Reverse,{p_,k_}:>Table[PrimePi[p],{k}]]]]];
strfacs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[strfacs[n/d],Min@@#>d&]],{d,Rest[Divisors[n]]}]];
Table[Length[strfacs[Times@@Prime/@nrmptn[n]]],{n,60}]
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permcount(v) = {my(m=1, s=0, k=0, t); for(i=1, #v, t=v[i]; k=if(i>1&&t==v[i-1], k+1, 1); m*=t*k; s+=t); s!/m}
sig(n)={my(f=factor(n)); concat(vector(#f~, i, vector(f[i, 2], j, primepi(f[i, 1]))))}
count(sig)={my(r=0, A=O(x*x^vecmax(sig))); for(n=1, vecsum(sig)+1, my(s=0); forpart(p=n, my(q=1/prod(i=1, #p, 1 - x^p[i] + A)); s+=prod(i=1, #sig, polcoef(q, sig[i]))*(-1)^#p*permcount(p)); r+=(-1)^n*s/n!); r/2}
a(n)={if(n==1, 1, count(sig(n)))} \\ Andrew Howroyd, Dec 18 2018
A318285
Number of non-isomorphic multiset partitions of a multiset whose multiplicities are the prime indices of n.
Original entry on oeis.org
1, 1, 2, 2, 3, 4, 5, 3, 7, 7, 7, 9, 11, 12, 16, 5, 15, 17, 22, 16, 29, 19, 30, 16, 21, 30, 23, 29, 42, 52, 56, 7, 47, 45, 57, 43, 77, 67, 77, 31, 101, 98, 135, 47, 85, 97, 176, 29, 66, 64, 118, 77, 231, 69, 97, 57, 181, 139, 297, 137, 385, 195, 166, 11, 162, 171, 490, 118
Offset: 1
Non-isomorphic representatives of the a(12) = 9 multiset partitions of {1,1,2,3}:
{{1,1,2,3}}
{{1},{1,2,3}}
{{2},{1,1,3}}
{{1,1},{2,3}}
{{1,2},{1,3}}
{{1},{1},{2,3}}
{{1},{2},{1,3}}
{{2},{3},{1,1}}
{{1},{1},{2},{3}}
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\\ See links in A339645 for combinatorial species functions.
sig(n)={my(f=factor(n), sig=vector(primepi(vecmax(f[,1])))); for(i=1, #f~, sig[primepi(f[i,1])]=f[i,2]); sig}
C(sig)={my(n=sum(i=1, #sig, i*sig[i]), A=Vec(symGroupSeries(n)-1), B=O(x*x^n), c=prod(i=1, #sig, if(sig[i], sApplyCI(A[sig[i]], sig[i], A[i], i), 1))); polcoef(OgfSeries(sCartProd(c*x^n + B, sExp(x*Ser(A) + B))), n)}
a(n)={if(n==1, 1, C(sig(n)))} \\ Andrew Howroyd, Jan 17 2023
A318362
Number of non-isomorphic set multipartitions (multisets of sets) of a multiset whose multiplicities are the prime indices of n.
Original entry on oeis.org
1, 1, 1, 2, 1, 2, 1, 3, 3, 2, 1, 5, 1, 2, 3, 5, 1, 7, 1, 5, 3, 2, 1, 9, 4, 2, 8, 5, 1, 10
Offset: 1
Non-isomorphic representatives of the a(12) = 5 set multipartitions of {1,1,2,3}:
{{1},{1,2,3}}
{{1,2},{1,3}}
{{1},{1},{2,3}}
{{1},{2},{1,3}}
{{1},{1},{2},{3}}
A318371
Number of non-isomorphic strict set multipartitions (sets of sets) of a multiset whose multiplicities are the prime indices of n.
Original entry on oeis.org
1, 1, 0, 2, 0, 1, 0, 3, 1, 0, 0, 3, 0, 0, 0, 5, 0, 4, 0, 1, 0, 0, 0, 6, 0, 0, 4, 0, 0, 2
Offset: 1
Non-isomorphic representatives of the a(24) = 6 strict set multipartitions of {1,1,2,3,4}:
{{1},{1,2,3,4}}
{{1,2},{1,3,4}}
{{1},{2},{1,3,4}}
{{1},{1,2},{3,4}}
{{2},{1,3},{1,4}}
{{1},{2},{3},{1,4}}
A318357
Number of non-isomorphic strict multiset partitions of the multiset of prime indices of n.
Original entry on oeis.org
1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 3, 2, 2, 1, 5, 1, 2, 2, 3, 1, 3, 1, 3, 2, 2, 2, 4, 1, 2, 2, 5, 1, 3, 1, 3, 3, 2, 1, 7, 1, 3, 2, 3, 1, 5, 2, 5, 2, 2, 1, 7, 1, 2, 3, 4, 2, 3, 1, 3, 2, 3, 1, 9, 1, 2, 3, 3, 2, 3, 1, 7, 2, 2, 1, 7, 2, 2, 2
Offset: 1
Non-isomorphic representatives of the a(48) = 7 strict multiset partitions of {1,1,1,1,2}:
{{1,1,1,1,2}}
{{1},{1,1,1,2}}
{{2},{1,1,1,1}}
{{1,1},{1,1,2}}
{{1,2},{1,1,1}}
{{1},{2},{1,1,1}}
{{1},{1,1},{1,2}}
Showing 1-7 of 7 results.