A324748
Number of strict integer partitions of n containing all prime indices of the parts.
Original entry on oeis.org
1, 1, 0, 1, 0, 1, 1, 1, 0, 2, 1, 2, 3, 2, 2, 4, 3, 4, 3, 5, 6, 9, 8, 7, 8, 11, 12, 13, 15, 17, 22, 22, 20, 28, 31, 32, 36, 41, 43, 53, 53, 59, 70, 76, 77, 89, 99, 108, 124, 135, 139, 160, 172, 188, 209, 229, 243, 274, 298, 315, 353, 391, 417, 457, 496, 538, 588
Offset: 0
The first 15 terms count the following integer partitions.
1: (1)
3: (2,1)
5: (4,1)
6: (3,2,1)
7: (4,2,1)
9: (8,1)
9: (6,2,1)
10: (4,3,2,1)
11: (8,2,1)
11: (5,3,2,1)
12: (9,2,1)
12: (7,4,1)
12: (6,3,2,1)
13: (8,4,1)
13: (6,4,2,1)
14: (8,3,2,1)
14: (7,4,2,1)
15: (12,2,1)
15: (9,3,2,1)
15: (8,4,2,1)
15: (5,4,3,2,1)
An example for n = 6 is (20,18,11,5,3,2,1), with prime indices:
20: {1,1,3}
18: {1,2,2}
11: {5}
5: {3}
3: {2}
2: {1}
1: {}
All of these prime indices {1,2,3,5} belong to the partition, as required.
Cf.
A000720,
A001462,
A007097,
A074971,
A078374,
A112798,
A276625,
A279861,
A290689,
A290760,
A305713.
-
Table[Length[Select[IntegerPartitions[n],UnsameQ@@#&&SubsetQ[#,PrimePi/@First/@Join@@FactorInteger/@DeleteCases[#,1]]&]],{n,0,30}]
A324763
Number of maximal subsets of {2...n} containing no prime indices of the elements.
Original entry on oeis.org
1, 1, 2, 2, 2, 3, 6, 6, 6, 6, 10, 10, 16, 16, 16, 16, 24, 24, 48, 48, 48, 48, 84, 84, 84, 84, 84, 84, 144, 144, 228, 228, 228, 228, 228, 228, 420, 420, 420, 420, 648, 648, 1080, 1080, 1080, 1080, 1800, 1800, 1800, 1800, 1800, 1800, 3600, 3600, 3600, 3600, 3600
Offset: 1
The a(1) = 1 through a(9) = 6 subsets:
{} {2} {2} {2,4} {3,4} {2,4,5} {2,4,5} {2,4,5,8} {2,4,5,8}
{3} {3,4} {2,4,5} {3,4,6} {2,5,7} {2,5,7,8} {2,5,7,8}
{4,5,6} {3,4,6} {3,4,6,8} {3,4,6,8,9}
{3,6,7} {3,6,7,8} {3,6,7,8,9}
{4,5,6} {4,5,6,8} {4,5,6,8,9}
{5,6,7} {5,6,7,8} {5,6,7,8,9}
The non-maximal version is
A324742.
The version for subsets of {1...n} is
A324741.
-
maxim[s_]:=Complement[s,Last/@Select[Tuples[s,2],UnsameQ@@#&&SubsetQ@@#&]];
Table[Length[maxim[Select[Subsets[Range[2,n]],Intersection[#,PrimePi/@First/@Join@@FactorInteger/@#]=={}&]]],{n,10}]
-
pset(n)={my(b=0, f=factor(n)[, 1]); sum(i=1, #f, 1<<(primepi(f[i])))}
a(n)={my(p=vector(n-1, k, pset(k+1)>>1), d=0); for(i=1, #p, d=bitor(d, p[i]));
my(ismax(b)=my(e=0); forstep(k=#p, 1, -1, if(bittest(b,k), e=bitor(e,p[k]), if(!bittest(e,k) && !bitand(p[k], b), return(0)) )); 1);
((k, b)->if(k>#p, ismax(b), my(f=!bitand(p[k], b)); if(!f || bittest(d, k), self()(k+1, b)) + if(f, self()(k+1, b+(1<Andrew Howroyd, Aug 26 2019
A358453
Number of transitive ordered rooted trees with n nodes.
Original entry on oeis.org
1, 1, 1, 2, 4, 8, 17, 37, 83, 190, 444, 1051, 2518, 6090, 14852
Offset: 1
The a(1) = 1 through a(7) = 17 trees:
o (o) (oo) (ooo) (oooo) (ooooo) (oooooo)
(o(o)) (o(o)o) (o(o)oo) (o(o)ooo)
(o(oo)) (o(oo)o) (o(oo)oo)
(oo(o)) (o(ooo)) (o(ooo)o)
(oo(o)o) (o(oooo))
(oo(oo)) (oo(o)oo)
(ooo(o)) (oo(oo)o)
(o(o)(o)) (oo(ooo))
(ooo(o)o)
(ooo(oo))
(oooo(o))
(o(o)(o)o)
(o(o)(oo))
(o(o)o(o))
(o(oo)(o))
(oo(o)(o))
(o(o)((o)))
A306844 counts anti-transitive rooted trees.
-
aot[n_]:=If[n==1,{{}},Join@@Table[Tuples[aot/@c],{c,Join@@Permutations/@IntegerPartitions[n-1]}]];
Table[Length[Select[aot[n],Function[t,And@@Table[Complement[t[[k]],Take[t,k]]=={},{k,Length[t]}]]]],{n,10}]
A324766
Matula-Goebel numbers of recursively anti-transitive rooted trees.
Original entry on oeis.org
1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 16, 17, 19, 20, 21, 22, 23, 25, 27, 29, 31, 32, 33, 34, 35, 40, 44, 46, 49, 50, 51, 53, 57, 59, 62, 63, 64, 67, 68, 71, 73, 77, 79, 80, 81, 83, 85, 87, 88, 92, 93, 95, 97, 99, 100, 103, 109, 115, 118, 121, 124, 125, 127, 128
Offset: 1
The sequence of recursively anti-transitive rooted trees together with their Matula-Goebel numbers begins:
1: o
2: (o)
3: ((o))
4: (oo)
5: (((o)))
7: ((oo))
8: (ooo)
9: ((o)(o))
10: (o((o)))
11: ((((o))))
16: (oooo)
17: (((oo)))
19: ((ooo))
20: (oo((o)))
21: ((o)(oo))
22: (o(((o))))
23: (((o)(o)))
25: (((o))((o)))
27: ((o)(o)(o))
29: ((o((o))))
31: (((((o)))))
32: (ooooo)
33: ((o)(((o))))
34: (o((oo)))
35: (((o))(oo))
40: (ooo((o)))
44: (oo(((o))))
46: (o((o)(o)))
49: ((oo)(oo))
50: (o((o))((o)))
-
primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
totantiQ[n_]:=And[Intersection[Union@@primeMS/@primeMS[n],primeMS[n]]=={},And@@totantiQ/@primeMS[n]];
Select[Range[100],totantiQ]
A324767
Number of recursively anti-transitive rooted identity trees with n nodes.
Original entry on oeis.org
1, 1, 1, 1, 2, 3, 5, 9, 17, 33, 63, 126, 254, 511, 1039, 2124, 4371, 9059, 18839, 39339, 82385, 173111, 364829, 771010, 1633313
Offset: 1
The a(4) = 1 through a(8) = 9 recursively anti-transitive rooted identity trees:
(((o))) (o((o))) ((o((o)))) (((o((o))))) ((o)(o((o))))
((((o)))) (o(((o)))) ((o)(((o)))) (o((o((o)))))
(((((o))))) ((o(((o))))) ((((o((o))))))
(o((((o))))) (((o)(((o)))))
((((((o)))))) (((o(((o))))))
((o)((((o)))))
((o((((o))))))
(o(((((o))))))
(((((((o)))))))
-
iallt[n_]:=Select[Union[Sort/@Join@@(Tuples[iallt/@#]&/@IntegerPartitions[n-1])],UnsameQ@@#&&Intersection[Union@@#,#]=={}&];
Table[Length[iallt[n]],{n,10}]
A324770
Number of fully anti-transitive rooted identity trees with n nodes.
Original entry on oeis.org
1, 1, 1, 1, 2, 3, 6, 13, 27, 58, 128, 286, 640, 1452, 3308, 7594, 17512, 40591, 94449, 220672
Offset: 1
The a(1) = 1 through a(7) = 6 fully anti-transitive rooted identity trees:
o (o) ((o)) (((o))) ((o(o))) (((o(o)))) ((o(o(o))))
((((o)))) ((o((o)))) ((((o(o)))))
(((((o))))) (((o)((o))))
(((o((o)))))
((o(((o)))))
((((((o))))))
-
idall[n_]:=If[n==1,{{}},Select[Union[Sort/@Join@@(Tuples[idall/@#]&/@IntegerPartitions[n-1])],UnsameQ@@#&]];
Table[Length[Select[idall[n],Intersection[Union@@Rest[FixedPointList[Union@@#&,#]],#]=={}&]],{n,10}]
A324769
Matula-Goebel numbers of fully anti-transitive rooted trees.
Original entry on oeis.org
1, 2, 3, 4, 5, 7, 8, 9, 11, 13, 16, 17, 19, 21, 23, 25, 27, 29, 31, 32, 35, 37, 41, 43, 47, 49, 51, 53, 57, 59, 61, 63, 64, 65, 67, 71, 73, 77, 79, 81, 83, 85, 89, 91, 95, 97, 101, 103, 107, 109, 113, 115, 121, 125, 127, 128, 129, 131, 133, 137, 139, 143, 147
Offset: 1
The sequence of fully anti-transitive rooted trees together with their Matula-Goebel numbers begins:
1: o
2: (o)
3: ((o))
4: (oo)
5: (((o)))
7: ((oo))
8: (ooo)
9: ((o)(o))
11: ((((o))))
13: ((o(o)))
16: (oooo)
17: (((oo)))
19: ((ooo))
21: ((o)(oo))
23: (((o)(o)))
25: (((o))((o)))
27: ((o)(o)(o))
29: ((o((o))))
31: (((((o)))))
32: (ooooo)
35: (((o))(oo))
37: ((oo(o)))
41: (((o(o))))
43: ((o(oo)))
47: (((o)((o))))
49: ((oo)(oo))
-
primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
fullantiQ[n_]:=Intersection[Union@@Rest[FixedPointList[Union@@primeMS/@#&,primeMS[n]]],primeMS[n]]=={};
Select[Range[100],fullantiQ]
A358456
Number of recursively bi-anti-transitive ordered rooted trees with n nodes.
Original entry on oeis.org
1, 1, 2, 3, 7, 17, 47, 117, 321, 895, 2556, 7331, 21435, 63116, 187530
Offset: 1
The a(1) = 1 through a(6) = 17 trees:
o (o) (oo) (ooo) (oooo) (ooooo)
((o)) ((oo)) ((ooo)) ((oooo))
(((o))) (((o))o) (((o))oo)
(((oo))) (((oo))o)
((o)(o)) (((ooo)))
(o((o))) ((o)(oo))
((((o)))) ((oo)(o))
(o((o))o)
(o((oo)))
(oo((o)))
((((o)))o)
((((o))o))
((((oo))))
(((o)(o)))
((o((o))))
(o(((o))))
(((((o)))))
A306844 counts anti-transitive rooted trees.
Cf.
A318185,
A324695,
A324751,
A324756,
A324758,
A324764,
A324767,
A324768,
A324838,
A324840,
A324844.
-
aot[n_]:=If[n==1,{{}},Join@@Table[Tuples[aot/@c],{c,Join@@Permutations/@IntegerPartitions[n-1]}]];
Table[Length[Select[aot[n],FreeQ[#,{_,x_,_,{_,x_,_},_}|{_,{_,x_,_},_,x_,_}]&]],{n,10}]
A358454
Number of weakly transitive ordered rooted trees with n nodes.
Original entry on oeis.org
1, 1, 1, 3, 6, 13, 33, 80, 201, 509, 1330, 3432, 8982, 23559, 62189
Offset: 1
The a(1) = 1 through a(6) = 13 trees:
o (o) (oo) (ooo) (oooo) (ooooo)
((o)o) ((o)oo) ((o)ooo)
(o(o)) ((oo)o) ((oo)oo)
(o(o)o) ((ooo)o)
(o(oo)) (o(o)oo)
(oo(o)) (o(oo)o)
(o(ooo))
(oo(o)o)
(oo(oo))
(ooo(o))
((o)(o)o)
((o)o(o))
(o(o)(o))
A306844 counts anti-transitive rooted trees.
-
aot[n_]:=If[n==1,{{}},Join@@Table[Tuples[aot/@c],{c,Join@@Permutations/@IntegerPartitions[n-1]}]];
Table[Length[Select[aot[n],Complement[Union@@#,#]=={}&]],{n,10}]
A358455
Number of recursively anti-transitive ordered rooted trees with n nodes.
Original entry on oeis.org
1, 1, 2, 4, 10, 26, 72, 206, 608, 1830, 5612, 17442, 54866, 174252, 558072, 1800098
Offset: 1
The a(1) = 1 through a(5) = 10 trees:
o (o) (oo) (ooo) (oooo)
((o)) ((o)o) ((o)oo)
((oo)) ((oo)o)
(((o))) ((ooo))
(((o))o)
(((o)o))
(((oo)))
((o)(o))
(o((o)))
((((o))))
A306844 counts anti-transitive rooted trees.
Cf.
A318185,
A324695,
A324751,
A324756,
A324758,
A324764,
A324767,
A324768,
A324838,
A324840,
A324844.
-
aot[n_]:=If[n==1,{{}},Join@@Table[Tuples[aot/@c],{c,Join@@Permutations/@IntegerPartitions[n-1]}]];
Table[Length[Select[aot[n],FreeQ[#,{_,x_,_,{_,x_,_},_}]&]],{n,10}]
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