A339563
Squarefree numbers > 1 whose smallest prime index divides all the other prime indices.
Original entry on oeis.org
2, 3, 5, 6, 7, 10, 11, 13, 14, 17, 19, 21, 22, 23, 26, 29, 30, 31, 34, 37, 38, 39, 41, 42, 43, 46, 47, 53, 57, 58, 59, 61, 62, 65, 66, 67, 70, 71, 73, 74, 78, 79, 82, 83, 86, 87, 89, 94, 97, 101, 102, 103, 106, 107, 109, 110, 111, 113, 114, 115, 118, 122, 127
Offset: 1
The sequence of terms together with their prime indices begins:
2: {1} 29: {10} 59: {17}
3: {2} 30: {1,2,3} 61: {18}
5: {3} 31: {11} 62: {1,11}
6: {1,2} 34: {1,7} 65: {3,6}
7: {4} 37: {12} 66: {1,2,5}
10: {1,3} 38: {1,8} 67: {19}
11: {5} 39: {2,6} 70: {1,3,4}
13: {6} 41: {13} 71: {20}
14: {1,4} 42: {1,2,4} 73: {21}
17: {7} 43: {14} 74: {1,12}
19: {8} 46: {1,9} 78: {1,2,6}
21: {2,4} 47: {15} 79: {22}
22: {1,5} 53: {16} 82: {1,13}
23: {9} 57: {2,8} 83: {23}
26: {1,6} 58: {1,10} 86: {1,14}
The complement of the not necessarily squarefree version is
A342193.
A000070 counts partitions with a selected part.
A001221 counts distinct prime factors.
A338470 counts partitions with no dividing part.
-
Select[Range[2,100],SquareFreeQ[#]&&With[{p=PrimePi/@First/@FactorInteger[#]},And@@IntegerQ/@(p/Min@@p)]&]
A343382
Number of strict integer partitions of n with either (1) no part dividing all the others or (2) no part divisible by all the others.
Original entry on oeis.org
1, 0, 0, 0, 0, 1, 1, 2, 3, 4, 6, 9, 9, 13, 18, 21, 26, 34, 38, 48, 57, 67, 81, 99, 110, 133, 157, 183, 211, 250, 282, 330, 380, 437, 502, 575, 648, 748, 852, 967, 1095, 1250, 1405, 1597, 1801, 2029, 2287, 2579, 2883, 3245, 3638, 4077, 4557, 5107, 5691, 6356
Offset: 0
The a(0) = 1 through a(11) = 9 partitions (empty columns indicated by dots):
() . . . . (3,2) (3,2,1) (4,3) (5,3) (5,4) (6,4) (6,5)
(5,2) (4,3,1) (7,2) (7,3) (7,4)
(5,2,1) (4,3,2) (5,3,2) (8,3)
(5,3,1) (5,4,1) (9,2)
(7,2,1) (5,4,2)
(4,3,2,1) (6,3,2)
(6,4,1)
(7,3,1)
(5,3,2,1)
The first condition alone gives
A341450.
The second condition alone gives
A343377.
The version for "and" instead of "or" is
A343379.
A000070 counts partitions with a selected part.
A006128 counts partitions with a selected position.
A015723 counts strict partitions with a selected part.
A167865 counts strict chains of divisors > 1 summing to n.
A339564 counts factorizations with a selected factor.
Cf.
A083710,
A097986,
A130689,
A200745,
A264401,
A338470,
A339562,
A342193,
A343337,
A343338,
A343341,
A343342.
-
Table[Length[Select[IntegerPartitions[n],#=={}||UnsameQ@@#&&!And@@IntegerQ/@(#/Min@@#)||UnsameQ@@#&&!And@@IntegerQ/@(Max@@#/#)&]],{n,0,30}]
A339562
Squarefree numbers with no prime index dividing all the other prime indices.
Original entry on oeis.org
1, 15, 33, 35, 51, 55, 69, 77, 85, 91, 93, 95, 105, 119, 123, 141, 143, 145, 155, 161, 165, 177, 187, 195, 201, 203, 205, 209, 215, 217, 219, 221, 231, 247, 249, 253, 255, 265, 285, 287, 291, 295, 299, 301, 309, 323, 327, 329, 335, 341, 345, 355, 357, 377, 381
Offset: 1
The sequence of terms together with their prime indices begins:
1: {} 141: {2,15} 219: {2,21}
15: {2,3} 143: {5,6} 221: {6,7}
33: {2,5} 145: {3,10} 231: {2,4,5}
35: {3,4} 155: {3,11} 247: {6,8}
51: {2,7} 161: {4,9} 249: {2,23}
55: {3,5} 165: {2,3,5} 253: {5,9}
69: {2,9} 177: {2,17} 255: {2,3,7}
77: {4,5} 187: {5,7} 265: {3,16}
85: {3,7} 195: {2,3,6} 285: {2,3,8}
91: {4,6} 201: {2,19} 287: {4,13}
93: {2,11} 203: {4,10} 291: {2,25}
95: {3,8} 205: {3,13} 295: {3,17}
105: {2,3,4} 209: {5,8} 299: {6,9}
119: {4,7} 215: {3,14} 301: {4,14}
123: {2,13} 217: {4,11} 309: {2,27}
The squarefree complement is
A339563.
These partitions are counted by
A341450.
The not necessarily squarefree version is
A342193.
A000070 counts partitions with a selected part.
A001221 counts distinct prime factors.
A349054
Number of alternating strict compositions of n. Number of alternating (up/down or down/up) permutations of strict integer partitions of n.
Original entry on oeis.org
1, 1, 1, 3, 3, 5, 9, 11, 15, 21, 35, 41, 59, 75, 103, 155, 193, 255, 339, 443, 569, 841, 1019, 1365, 1743, 2295, 2879, 3785, 5151, 6417, 8301, 10625, 13567, 17229, 21937, 27509, 37145, 45425, 58345, 73071, 93409, 115797, 147391, 182151, 229553, 297061, 365625
Offset: 0
The a(1) = 1 through a(7) = 11 compositions:
(1) (2) (3) (4) (5) (6) (7)
(1,2) (1,3) (1,4) (1,5) (1,6)
(2,1) (3,1) (2,3) (2,4) (2,5)
(3,2) (4,2) (3,4)
(4,1) (5,1) (4,3)
(1,3,2) (5,2)
(2,1,3) (6,1)
(2,3,1) (1,4,2)
(3,1,2) (2,1,4)
(2,4,1)
(4,1,2)
Ranking sequences are put in parentheses below.
The unordered case (partitions) is
A065033.
Cf.
A000111,
A008965,
A015723,
A114901,
A128761,
A129852,
A129853,
A218074,
A333213,
A344614,
A345164,
A345194,
A349060,
A349795.
-
g:= proc(u, o) option remember;
`if`(u+o=0, 1, add(g(o-1+j, u-j), j=1..u))
end:
b:= proc(n, k) option remember; `if`(k<0 or n<0, 0,
`if`(k=0, `if`(n=0, 2, 0), b(n-k, k)+b(n-k, k-1)))
end:
a:= n-> add(b(n, k)*g(k, 0), k=0..floor((sqrt(8*n+1)-1)/2))-1:
seq(a(n), n=0..46); # Alois P. Heinz, Dec 22 2021
-
wigQ[y_]:=Or[Length[y]==0,Length[Split[y]]==Length[y]&&Length[Split[Sign[Differences[y]]]]==Length[y]-1];
Table[Length[Select[Join@@Permutations/@Select[IntegerPartitions[n],UnsameQ@@#&],wigQ]],{n,0,15}]
Original entry on oeis.org
1, 1, 1, 2, 1, 4, 1, 5, 3, 7, 1, 14, 1, 13, 8, 20, 1, 33, 1, 40, 14, 44, 1, 85, 6, 79, 25, 117, 1, 181, 1, 196, 45, 233, 17, 389, 1, 387, 80, 545, 1, 750, 1, 839, 165, 1004, 1, 1516, 12, 1612, 234, 2040, 1, 2766, 48, 3142, 388, 3720, 1, 5295, 1, 5606, 663, 7038, 83, 9194, 1, 10379, 1005
Offset: 1
From _Gus Wiseman_, Apr 18 2021: (Start)
The a(6) = 4 through a(12) = 13 partitions:
(6) (7) (8) (9) (10) (11) (12)
(3,3) (4,4) (6,3) (5,5) (6,6)
(4,2) (6,2) (3,3,3) (8,2) (8,4)
(2,2,2) (4,2,2) (4,4,2) (9,3)
(2,2,2,2) (6,2,2) (10,2)
(4,2,2,2) (4,4,4)
(2,2,2,2,2) (6,3,3)
(6,4,2)
(8,2,2)
(3,3,3,3)
(4,4,2,2)
(6,2,2,2)
(4,2,2,2,2)
(2,2,2,2,2,2)
(End)
- L. M. Chawla, M. O. Levan and J. E. Maxfield, On a restricted partition function and its tables, J. Natur. Sci. and Math., 12 (1972), 95-101.
The complement (except also without 1's) is counted by
A338470.
A000070 counts partitions with a selected part.
A006128 counts partitions with a selected position.
A167865 counts strict chains of divisors > 1 summing to n.
A339564 counts factorizations with a selected factor.
-
with(combinat): with(numtheory): a := proc(n) c := 0: l := sort(convert(divisors(n), list)): for i from 1 to nops(l)-1 do c := c+numbpart(l[i]-1) od: RETURN(c): end: for j from 2 to 100 do printf(`%d,`,a(j)) od: # James Sellers, Jun 21 2003
# second Maple program:
a:= n-> max(1, add(combinat[numbpart](d-1), d=numtheory[divisors](n) minus {n})):
seq(a(n), n=1..69); # Alois P. Heinz, Feb 15 2023
-
a[n_] := If[n==1, 1, Sum[PartitionsP[d-1], {d, Most@Divisors[n]}]];
Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Feb 15 2023 *)
A130714
Number of partitions of n such that every part divides the largest part and such that the smallest part divides every part.
Original entry on oeis.org
1, 2, 3, 5, 6, 10, 11, 16, 19, 26, 27, 41, 42, 55, 64, 81, 83, 114, 116, 151, 168, 202, 210, 277, 289, 348, 382, 460, 478, 604, 623, 747, 812, 942, 1006, 1223, 1269, 1479, 1605, 1870, 1959, 2329, 2434, 2818, 3056, 3458, 3653, 4280, 4493, 5130, 5507, 6231, 6580
Offset: 1
From _Gus Wiseman_, Apr 18 2021: (Start)
The a(1) = 1 though a(8) = 16 partitions:
(1) (2) (3) (4) (5) (6) (7) (8)
(11) (21) (22) (41) (33) (61) (44)
(111) (31) (221) (42) (331) (62)
(211) (311) (51) (421) (71)
(1111) (2111) (222) (511) (422)
(11111) (411) (2221) (611)
(2211) (4111) (2222)
(3111) (22111) (3311)
(21111) (31111) (4211)
(111111) (211111) (5111)
(1111111) (22211)
(41111)
(221111)
(311111)
(2111111)
(11111111)
(End)
The second condition alone gives
A083710.
The first condition alone gives
A130689.
The Heinz numbers of these partitions are the complement of
A343343.
The complement is counted by
A343346.
A000070 counts partitions with a selected part.
A006128 counts partitions with a selected position.
A015723 counts strict partitions with a selected part.
-
A130714 := proc(n) local gf,den,i,k,j ; gf := 0 ; for i from 0 to n do for j from 1 to n/(1+i) do den := 1 ; for k in numtheory[divisors](i) do den := den*(1-x^(j*k)) ; od ; gf := taylor(gf+x^(j+i*j)/den,x=0,n+1) ; od ; od: coeftayl(gf,x=0,n) ; end: seq(A130714(n),n=1..60) ; # R. J. Mathar, Oct 28 2007
-
Table[If[n==0,1,Length[Select[IntegerPartitions[n],And@@IntegerQ/@(#/Min@@#)&&And@@IntegerQ/@(Max@@#/#)&]]],{n,0,30}] (* Gus Wiseman, Apr 18 2021 *)
A210485
Number T(n,k) of parts in all partitions of n in which no part occurs more than k times; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
Original entry on oeis.org
0, 0, 1, 0, 1, 3, 0, 3, 3, 6, 0, 3, 8, 8, 12, 0, 5, 11, 15, 15, 20, 0, 8, 17, 24, 29, 29, 35, 0, 10, 23, 36, 41, 47, 47, 54, 0, 13, 36, 50, 65, 71, 78, 78, 86, 0, 18, 48, 75, 91, 104, 111, 119, 119, 128, 0, 25, 69, 102, 132, 150, 165, 173, 182, 182, 192
Offset: 0
T(6,2) = 17: [6], [5,1], [4,2], [3,3], [4,1,1], [3,2,1], [2,2,1,1].
Triangle T(n,k) begins:
0;
0, 1;
0, 1, 3;
0, 3, 3, 6;
0, 3, 8, 8, 12;
0, 5, 11, 15, 15, 20;
0, 8, 17, 24, 29, 29, 35;
0, 10, 23, 36, 41, 47, 47, 54;
0, 13, 36, 50, 65, 71, 78, 78, 86;
...
Columns k=0-10 give:
A000004,
A015723,
A185350,
A117148,
A320607,
A320608,
A320609,
A320610,
A320611,
A320612,
A320613.
-
b:= proc(n, i, k) option remember; `if`(n=0, [1, 0], `if`(i<1, [0, 0],
add((l->[l[1], l[2]+l[1]*j])(b(n-i*j, i-1, k)), j=0..min(n/i, k))))
end:
T:= (n, k)-> b(n, n, k)[2]:
seq(seq(T(n, k), k=0..n), n=0..12);
-
b[n_, i_, k_] := b[n, i, k] = If[n == 0, {1, 0}, If[i < 1, {0, 0}, Sum[b[n-i*j, i-1, k] /. l_List :> {l[[1]], l[[2]] + l[[1]]*j}, {j, 0, Min[n/i, k]}]]]; T[n_, k_] := b[n, n, k][[2]]; Table[Table[T[n, k], {k, 0, n}], {n, 0, 12}] // Flatten (* Jean-François Alcover, Dec 27 2013, translated from Maple *)
A343377
Number of strict integer partitions of n with no part divisible by all the others.
Original entry on oeis.org
1, 0, 0, 0, 0, 1, 1, 2, 3, 4, 6, 8, 9, 13, 18, 21, 26, 32, 38, 47, 57, 66, 80, 95, 110, 132, 157, 181, 211, 246, 282, 327, 379, 435, 500, 570, 648, 743, 849, 963, 1094, 1241, 1404, 1592, 1799, 2025, 2282, 2568, 2882, 3239, 3634, 4066, 4554, 5094, 5686, 6346
Offset: 0
The a(5) = 1 through a(12) = 9 partitions:
(3,2) (3,2,1) (4,3) (5,3) (5,4) (6,4) (6,5) (7,5)
(5,2) (4,3,1) (7,2) (7,3) (7,4) (5,4,3)
(5,2,1) (4,3,2) (5,3,2) (8,3) (6,4,2)
(5,3,1) (5,4,1) (9,2) (6,5,1)
(7,2,1) (5,4,2) (7,3,2)
(4,3,2,1) (6,4,1) (7,4,1)
(7,3,1) (8,3,1)
(5,3,2,1) (9,2,1)
(5,4,2,1)
The dual strict complement is
A097986.
The strict complement is counted by
A343347.
The case with smallest part not divisible by all the others is
A343379.
The case with smallest part divisible by all the others is
A343381.
A000070 counts partitions with a selected part.
A006128 counts partitions with a selected position.
A015723 counts strict partitions with a selected part.
A167865 counts strict chains of divisors > 1 summing to n.
A339564 counts factorizations with a selected factor.
Cf.
A083710,
A130689,
A200745,
A264401,
A338470,
A339562,
A343338,
A343342,
A343345,
A343346,
A343382.
-
Table[Length[Select[IntegerPartitions[n],#=={}||UnsameQ@@#&&!And@@IntegerQ/@(Max@@#/#)&]],{n,0,30}]
A343379
Number of strict integer partitions of n with no part dividing or divisible by all the other parts.
Original entry on oeis.org
1, 0, 0, 0, 0, 1, 0, 2, 1, 3, 3, 5, 3, 9, 9, 12, 12, 18, 18, 27, 27, 36, 41, 51, 51, 73, 80, 96, 105, 132, 137, 177, 188, 230, 253, 303, 320, 398, 431, 508, 550, 659, 705, 847, 913, 1063, 1165, 1359, 1452, 1716, 1856, 2134, 2329, 2688, 2894, 3345, 3622, 4133
Offset: 0
The a(5) = 1 through a(13) = 9 partitions (empty column indicated by dot):
(3,2) . (4,3) (5,3) (5,4) (6,4) (6,5) (7,5) (7,6)
(5,2) (7,2) (7,3) (7,4) (5,4,3) (8,5)
(4,3,2) (5,3,2) (8,3) (7,3,2) (9,4)
(9,2) (10,3)
(5,4,2) (11,2)
(6,4,3)
(6,5,2)
(7,4,2)
(8,3,2)
The first condition alone gives
A341450.
The second condition alone gives
A343377.
The version for "or" instead of "and" is
A343382.
A000070 counts partitions with a selected part.
A006128 counts partitions with a selected position.
A015723 counts strict partitions with a selected part.
A167865 counts strict chains of divisors > 1 summing to n.
A339564 counts factorizations with a selected factor.
Cf.
A083710,
A097986,
A200745,
A264401,
A338470,
A339562,
A342193,
A343337,
A343341,
A343343,
A343346,
A343347.
-
Table[Length[Select[IntegerPartitions[n],#=={}||UnsameQ@@#&&!And@@IntegerQ/@(#/Min@@#)&&!And@@IntegerQ/@(Max@@#/#)&]],{n,0,30}]
A213177
Number T(n,k) of parts in all partitions of n with largest multiplicity k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
Original entry on oeis.org
0, 0, 1, 0, 1, 2, 0, 3, 0, 3, 0, 3, 5, 0, 4, 0, 5, 6, 4, 0, 5, 0, 8, 9, 7, 5, 0, 6, 0, 10, 13, 13, 5, 6, 0, 7, 0, 13, 23, 14, 15, 6, 7, 0, 8, 0, 18, 30, 27, 16, 13, 7, 8, 0, 9, 0, 25, 44, 33, 30, 18, 15, 8, 9, 0, 10, 0, 30, 58, 55, 36, 34, 15, 17, 9, 10, 0, 11
Offset: 0
T(6,1) = 8: partitions of 6 with largest multiplicity 1 are [3,2,1], [4,2], [5,1], [6], with 3+2+2+1 = 8 parts.
T(6,2) = 9: [2,2,1,1], [3,3], [4,1,1].
T(6,3) = 7: [2,2,2], [3,1,1,1].
T(6,4) = 5: [2,1,1,1,1].
T(6,5) = 0.
T(6,6) = 6: [1,1,1,1,1,1].
Triangle begins:
0;
0, 1;
0, 1, 2;
0, 3, 0, 3;
0, 3, 5, 0, 4;
0, 5, 6, 4, 0, 5;
0, 8, 9, 7, 5, 0, 6;
0, 10, 13, 13, 5, 6, 0, 7;
0, 13, 23, 14, 15, 6, 7, 0, 8;
...
Columns k=0-10 give:
A000004,
A015723,
A320372,
A320373,
A320374,
A320375,
A320376,
A320377,
A320378,
A320379,
A320380.
-
b:= proc(n, i, k) option remember; `if`(n=0, [1, 0], `if`(i<1, [0, 0],
add((l->[l[1], l[2]+l[1]*j])(b(n-i*j, i-1, k)), j=0..min(n/i, k))))
end:
T:= (n, k)-> b(n, n, k)[2] -b(n, n, k-1)[2]:
seq(seq(T(n, k), k=0..n), n=0..12);
-
b[n_, i_, k_] := b[n, i, k] = If[n == 0, {1, 0}, If[i < 1, {0, 0}, Sum[b[n-i*j, i-1, k] /. l_List :> {l[[1]], l[[2]] + l[[1]]*j}, {j, 0, Min[n/i, k]}]]]; T[, 0] = 0; T[n, k_] := b[n, n, k][[2]] - b[n, n, k-1][[2]]; Table[Table[T[n, k], {k, 0, n}], {n, 0, 12}] // Flatten (* Jean-François Alcover, Dec 27 2013, translated from Maple *)
Comments