cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-20 of 20 results.

A325769 Number of integer partitions of n whose distinct consecutive subsequences have different sums.

Original entry on oeis.org

1, 1, 2, 3, 4, 6, 7, 11, 12, 17, 19, 29, 28, 41, 42, 62, 61, 88, 87, 123, 121, 168, 164, 234, 225, 306, 306, 411, 401, 527, 533, 700, 689, 894, 885, 1163, 1150, 1452, 1469, 1866, 1835, 2333, 2346, 2913, 2913, 3638, 3619, 4511, 4537, 5497, 5576, 6859, 6827, 8263
Offset: 0

Views

Author

Gus Wiseman, May 21 2019

Keywords

Comments

For example (3,3,1,1) is counted under a(8) because it has distinct consecutive subsequences (), (1), (1,1), (3), (3,1), (3,1,1), (3,3), (3,3,1), (3,3,1,1), all of which have different sums.
The Heinz numbers of these partitions are given by A325778.

Examples

			The a(1) = 1 through a(8) = 12 partitions:
  (1)  (2)   (3)    (4)     (5)      (6)       (7)        (8)
       (11)  (21)   (22)    (32)     (33)      (43)       (44)
             (111)  (31)    (41)     (42)      (52)       (53)
                    (1111)  (221)    (51)      (61)       (62)
                            (311)    (222)     (322)      (71)
                            (11111)  (411)     (331)      (332)
                                     (111111)  (421)      (521)
                                               (511)      (611)
                                               (2221)     (2222)
                                               (4111)     (3311)
                                               (1111111)  (5111)
                                                          (11111111)
		

Crossrefs

Programs

  • Mathematica
    Table[Length[Select[IntegerPartitions[n],UnsameQ@@Total/@Union[ReplaceList[#,{_,s__,_}:>{s}]]&]],{n,0,30}]

Extensions

a(41)-a(53) from Fausto A. C. Cariboni, Feb 24 2021

A325853 Number of integer partitions of n such that every pair of distinct parts has a different quotient.

Original entry on oeis.org

1, 1, 2, 3, 5, 7, 11, 14, 21, 28, 39, 51, 69, 88, 116, 148, 193, 242, 309, 385, 484, 596, 746, 915, 1128, 1371, 1679, 2030, 2460, 2964, 3570, 4268, 5115, 6088, 7251, 8584, 10175, 12002, 14159, 16619, 19526, 22846, 26713, 31153, 36300, 42169, 48990, 56728
Offset: 0

Views

Author

Gus Wiseman, May 31 2019

Keywords

Comments

Also the number of integer partitions of n such that every orderless pair of (not necessarily distinct) parts has a different product.

Examples

			The a(1) = 1 through a(7) = 14 partitions:
  (1)  (2)   (3)    (4)     (5)      (6)       (7)
       (11)  (21)   (22)    (32)     (33)      (43)
             (111)  (31)    (41)     (42)      (52)
                    (211)   (221)    (51)      (61)
                    (1111)  (311)    (222)     (322)
                            (2111)   (321)     (331)
                            (11111)  (411)     (511)
                                     (2211)    (2221)
                                     (3111)    (3211)
                                     (21111)   (4111)
                                     (111111)  (22111)
                                               (31111)
                                               (211111)
                                               (1111111)
The one partition of 7 for which not every pair of distinct parts has a different quotient is (4,2,1).
		

Crossrefs

The subset case is A325860.
The maximal case is A325861.
The integer partition case is A325853.
The strict integer partition case is A325854.
Heinz numbers of the counterexamples are given by A325994.

Programs

  • Mathematica
    Table[Length[Select[IntegerPartitions[n],UnsameQ@@Divide@@@Subsets[Union[#],{2}]&]],{n,0,20}]

A325994 Heinz numbers of integer partitions such that not every ordered pair of distinct parts has a different quotient.

Original entry on oeis.org

42, 84, 126, 168, 210, 230, 252, 294, 336, 378, 390, 399, 420, 460, 462, 504, 546, 588, 630, 672, 690, 714, 742, 756, 780, 798, 840, 882, 920, 924, 966, 1008, 1050, 1092, 1134, 1150, 1170, 1176, 1197, 1218, 1260, 1302, 1344, 1365, 1380, 1386, 1428, 1470, 1484
Offset: 1

Views

Author

Gus Wiseman, Jun 02 2019

Keywords

Comments

The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).

Examples

			The sequence of terms together with their prime indices begins:
    42: {1,2,4}
    84: {1,1,2,4}
   126: {1,2,2,4}
   168: {1,1,1,2,4}
   210: {1,2,3,4}
   230: {1,3,9}
   252: {1,1,2,2,4}
   294: {1,2,4,4}
   336: {1,1,1,1,2,4}
   378: {1,2,2,2,4}
   390: {1,2,3,6}
   399: {2,4,8}
   420: {1,1,2,3,4}
   460: {1,1,3,9}
   462: {1,2,4,5}
   504: {1,1,1,2,2,4}
   546: {1,2,4,6}
   588: {1,1,2,4,4}
   630: {1,2,2,3,4}
   672: {1,1,1,1,1,2,4}
		

Crossrefs

The subset case is A325860.
The maximal case is A325861.
The integer partition case is A325853.
The strict integer partition case is A325854.
Heinz numbers of the counterexamples are given by A325994.

Programs

  • Mathematica
    Select[Range[1000],!UnsameQ@@Divide@@@Subsets[PrimePi/@First/@FactorInteger[#],{2}]&]

A325778 Heinz numbers of integer partitions whose distinct consecutive subsequences have different sums.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 64, 65, 66, 67, 68, 69, 71, 73, 74, 75, 76, 77
Offset: 1

Views

Author

Gus Wiseman, May 20 2019

Keywords

Comments

First differs from A299702 in having 462.
The enumeration of these partitions by sum is given by A325769.

Examples

			Most small numbers are in the sequence. However, the sequence of non-terms together with their prime indices begins:
  12: {1,1,2}
  24: {1,1,1,2}
  30: {1,2,3}
  36: {1,1,2,2}
  40: {1,1,1,3}
  48: {1,1,1,1,2}
  60: {1,1,2,3}
  63: {2,2,4}
  70: {1,3,4}
  72: {1,1,1,2,2}
  80: {1,1,1,1,3}
  84: {1,1,2,4}
  90: {1,2,2,3}
  96: {1,1,1,1,1,2}
		

Crossrefs

Programs

  • Mathematica
    primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
    Select[Range[100],UnsameQ@@Total/@Union[ReplaceList[primeMS[#],{_,s__,_}:>{s}]]&]

A325836 Number of integer partitions of n having n - 1 different submultisets.

Original entry on oeis.org

0, 0, 0, 1, 1, 2, 0, 3, 0, 5, 2, 2, 0, 15, 0, 2, 3, 25, 0, 17, 0, 18, 3, 2, 0, 150, 0, 2, 13, 24, 0, 43, 0, 351, 3, 2, 2, 383, 0, 2, 3, 341, 0, 60, 0, 37, 51, 2, 0, 3733, 0, 31, 3, 42, 0, 460, 1, 633, 3, 2, 0, 1780, 0, 2, 68, 12460, 0, 87, 0, 55, 3
Offset: 0

Views

Author

Gus Wiseman, May 29 2019

Keywords

Comments

The number of submultisets of a partition is the product of its multiplicities, each plus one.
The Heinz numbers of these partitions are given by A325694.

Examples

			The a(3) = 1 through a(13) = 15 partitions (empty columns not shown):
  (3)  (22)  (32)  (322)  (432)   (3322)  (32222)  (4432)
             (41)  (331)  (531)   (4411)  (71111)  (5332)
                   (511)  (621)                    (5422)
                          (3222)                   (5521)
                          (6111)                   (6322)
                                                   (6331)
                                                   (6511)
                                                   (7411)
                                                   (8221)
                                                   (8311)
                                                   (9211)
                                                   (33322)
                                                   (55111)
                                                   (322222)
                                                   (811111)
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i, p) option remember; `if`(n=0 or i=1,
          `if`(n=p-1, 1, 0), add(`if`(irem(p, j+1, 'r')=0,
          (w-> b(w, min(w, i-1), r))(n-i*j), 0), j=0..n/i))
        end:
    a:= n-> b(n$2,n-1):
    seq(a(n), n=0..80);  # Alois P. Heinz, Aug 17 2019
  • Mathematica
    Table[Length[Select[IntegerPartitions[n],Times@@(1+Length/@Split[#])==n-1&]],{n,0,30}]
    (* Second program: *)
    b[n_, i_, p_] := b[n, i, p] = If[n == 0 || i == 1,
         If[n == p - 1, 1, 0], Sum[If[Mod[p, j + 1] == 0, r = p/(j + 1);
         Function[w, b[w, Min[w, i - 1], r]][n - i*j], 0], {j, 0, n/i}]];
    a[n_] := b[n, n, n-1];
    a /@ Range[0, 80] (* Jean-François Alcover, May 12 2021, after Alois P. Heinz *)

A325854 Number of strict integer partitions of n such that every pair of distinct parts has a different quotient.

Original entry on oeis.org

1, 1, 1, 2, 2, 3, 4, 4, 6, 8, 9, 12, 13, 16, 20, 23, 30, 33, 41, 47, 52, 61, 75, 90, 98, 116, 132, 151, 173, 206, 226, 263, 297, 337, 387, 427, 488, 555, 623, 697, 782, 886, 984, 1108, 1240, 1374, 1545, 1726, 1910, 2120, 2358, 2614, 2903, 3218, 3567, 3933
Offset: 0

Views

Author

Gus Wiseman, May 31 2019

Keywords

Comments

Also the number of strict integer partitions of n such that every pair of (not necessarily distinct) parts has a different product.

Examples

			The a(1) = 1 through a(10) = 9 partitions (A = 10):
  (1)  (2)  (3)   (4)   (5)   (6)    (7)   (8)    (9)    (A)
            (21)  (31)  (32)  (42)   (43)  (53)   (54)   (64)
                        (41)  (51)   (52)  (62)   (63)   (73)
                              (321)  (61)  (71)   (72)   (82)
                                           (431)  (81)   (91)
                                           (521)  (432)  (532)
                                                  (531)  (541)
                                                  (621)  (631)
                                                         (721)
The two strict partitions of 13 such that not every pair of distinct parts has a different quotient are (9,3,1) and (6,4,2,1).
		

Crossrefs

The subset case is A325860.
The maximal case is A325861.
The integer partition case is A325853.
The strict integer partition case is A325854.
Heinz numbers of the counterexamples are given by A325994.

Programs

  • Mathematica
    Table[Length[Select[IntegerPartitions[n],UnsameQ@@#&&UnsameQ@@Divide@@@Subsets[Union[#],{2}]&]],{n,0,30}]

A325779 Heinz numbers of integer partitions for which every restriction to a subinterval has a different sum.

Original entry on oeis.org

1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 26, 29, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 46, 47, 51, 53, 55, 57, 58, 59, 61, 62, 65, 66, 67, 69, 71, 73, 74, 77, 78, 79, 82, 83, 85, 86, 87, 89, 91, 93, 94, 95, 97, 101, 102, 103, 105, 106, 107
Offset: 1

Views

Author

Gus Wiseman, May 20 2019

Keywords

Comments

First differs from A301899 in having 462.
The enumeration of these partitions by sum is given by A325768.

Examples

			Most small numbers are in the sequence. However, the sequence of non-terms together with their prime indices begins:
    4: {1,1}
    8: {1,1,1}
    9: {2,2}
   12: {1,1,2}
   16: {1,1,1,1}
   18: {1,2,2}
   20: {1,1,3}
   24: {1,1,1,2}
   25: {3,3}
   27: {2,2,2}
   28: {1,1,4}
   30: {1,2,3}
   32: {1,1,1,1,1}
   36: {1,1,2,2}
   40: {1,1,1,3}
   44: {1,1,5}
   45: {2,2,3}
   48: {1,1,1,1,2}
   49: {4,4}
   50: {1,3,3}
		

Crossrefs

Programs

  • Mathematica
    primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
    Select[Range[100],UnsameQ@@ReplaceList[primeMS[#],{_,s__,_}:>Plus[s]]&]

A325765 Number of integer partitions of n with a unique consecutive subsequence summing to every positive integer from 1 to n.

Original entry on oeis.org

1, 1, 1, 2, 1, 3, 1, 3, 2, 3, 1, 5, 1, 3, 3, 4, 1, 5, 1, 5, 3, 3, 1, 7, 2, 3, 3, 5, 1, 7, 1, 5, 3, 3, 3, 8, 1, 3, 3, 7, 1, 7, 1, 5, 5, 3, 1, 9, 2, 5, 3
Offset: 0

Views

Author

Gus Wiseman, May 20 2019

Keywords

Comments

After a(0) = 1, same as A032741(n + 1) (number of proper divisors of n + 1).
The Heinz numbers of these partitions are given by A325764.

Examples

			The a(1) = 1 through a(13) = 3 partitions:
  (1)  (11)  (21)   (1111)  (221)    (111111)  (2221)     (3311)
             (111)          (311)              (4111)     (11111111)
                            (11111)            (1111111)
.
  (22221)      (1111111111)  (33311)        (111111111111)  (2222221)
  (51111)                    (44111)                        (7111111)
  (111111111)                (222221)                       (1111111111111)
                             (611111)
                             (11111111111)
		

Crossrefs

Programs

  • Mathematica
    normQ[m_]:=Or[m=={},Union[m]==Range[Max[m]]];
    Table[Length[Select[IntegerPartitions[n],normQ[Total/@Union[ReplaceList[#,{_,s__,_}:>{s}]]]&&UnsameQ@@Total/@Union[ReplaceList[#,{_,s__,_}:>{s}]]&]],{n,0,20}]

A325777 Heinz numbers of integer partitions whose distinct consecutive subsequences do not have different sums.

Original entry on oeis.org

12, 24, 30, 36, 40, 48, 60, 63, 70, 72, 80, 84, 90, 96, 108, 112, 120, 126, 132, 140, 144, 150, 154, 156, 160, 165, 168, 180, 189, 192, 198, 200, 204, 210, 216, 220, 224, 228, 240, 252, 264, 270, 273, 276, 280, 286, 288, 300, 308, 312, 315, 320, 324, 325, 330
Offset: 1

Views

Author

Gus Wiseman, May 20 2019

Keywords

Comments

First differs from A299729 in lacking 462.
This sequence does not contain all multiples of its elements. For example, it contains 154 (with prime indices {1,4,5}) but not 462 (with prime indices {1,2,4,5}).

Crossrefs

Programs

  • Mathematica
    primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
    Select[Range[100],!UnsameQ@@Total/@Union[ReplaceList[primeMS[#],{_,s__,_}:>{s}]]&]

A334268 Number of compositions of n where every distinct subsequence (not necessarily contiguous) has a different sum.

Original entry on oeis.org

1, 1, 2, 4, 5, 10, 10, 24, 24, 43, 42, 88, 72, 136, 122, 242, 213, 392, 320, 630, 490, 916, 742, 1432, 1160, 1955, 1604, 2826, 2310, 3850, 2888, 5416, 4426, 7332, 5814, 10046, 7983, 12946, 10236, 17780, 14100, 22674, 17582, 30232, 23674, 37522, 29426, 49832
Offset: 0

Views

Author

Gus Wiseman, Jun 02 2020

Keywords

Comments

A composition of n is a finite sequence of positive integers summing to n.
The contiguous case is A325676.

Examples

			The a(1) = 1 through a(6) = 19 compositions:
  (1)  (2)    (3)      (4)        (5)          (6)
       (1,1)  (1,2)    (1,3)      (1,4)        (1,5)
              (2,1)    (2,2)      (2,3)        (2,4)
              (1,1,1)  (3,1)      (3,2)        (3,3)
                       (1,1,1,1)  (4,1)        (4,2)
                                  (1,1,3)      (5,1)
                                  (1,2,2)      (1,1,4)
                                  (2,2,1)      (2,2,2)
                                  (3,1,1)      (4,1,1)
                                  (1,1,1,1,1)  (1,1,1,1,1,1)
		

Crossrefs

These compositions are ranked by A334967.
Compositions where every restriction to a subinterval has a different sum are counted by A169942 and A325677 and ranked by A333222. The case of partitions is counted by A325768 and ranked by A325779.
Positive subset-sums of partitions are counted by A276024 and A299701.
Knapsack partitions are counted by A108917 and A325592 and ranked by A299702, while the strict case is counted by A275972 and ranked by A059519 and A301899.
Knapsack compositions are counted by A325676 and A325687 and ranked by A333223. The case of partitions is counted by A325769 and ranked by A325778, for which the number of distinct consecutive subsequences is given by A325770.

Programs

  • Maple
    b:= proc(n, s) option remember; `if`(n=0, 1, add((h->
          `if`(nops(h)=nops(map(l-> add(i, i=l), h)),
           b(n-j, h), 0))({s[], map(l-> [l[], j], s)[]}), j=1..n))
        end:
    a:= n-> b(n, {[]}):
    seq(a(n), n=0..23);  # Alois P. Heinz, Jun 03 2020
  • Mathematica
    Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],UnsameQ@@Total/@Union[Subsets[#]]&]],{n,0,15}]

Extensions

a(18)-a(47) from Alois P. Heinz, Jun 03 2020
Previous Showing 11-20 of 20 results.