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.

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A249620 Triangle read by rows: T(m,n) = number of partitions of the multiset with m elements and signature corresponding to n-th integer partition (A194602).

Original entry on oeis.org

1, 1, 2, 2, 5, 4, 3, 15, 11, 7, 9, 5, 52, 36, 21, 26, 12, 16, 7, 203, 135, 74, 92, 38, 52, 19, 66, 29, 31, 11, 877, 566, 296, 371, 141, 198, 64, 249, 98, 109, 30, 137, 47, 57, 15, 4140, 2610, 1315, 1663, 592, 850, 250, 1075, 392, 444, 105, 560
Offset: 0

Views

Author

Tilman Piesk, Nov 04 2014

Keywords

Comments

This triangle shows the same numbers in each row as A129306 and A096443, but in this arrangement the multisets in column n correspond to the n-th integer partition in the infinite order defined by A194602.
Row lengths: A000041 (partition numbers), Row sums: A035310
Columns: 0: A000110 (Bell), 1: A035098 (near-Bell), 2: A169587, 4: A169588
Last in row: end-1: A091437, end: A000041 (partition numbers)
The rightmost columns form a reflected version of the triangle A126442:
n 0 1 2 4 6 10 14 21 (A000041(1,2,3...)-1)
m
1 1
2 2 2
3 5 4 3
4 15 11 7 5
5 52 36 21 12 7
6 203 135 74 38 19 11
7 877 566 296 141 64 30 15
8 4140 2610 1315 592 250 105 45 22
A249619 shows the number of permutations of the same multisets.

Examples

			See "The T(5,2)=21 partitions of {1,1,1,2,3}" link. Similar links for m=1..8 are in "Partitions of multisets" (Wikiversity).
Triangle begins:
  n     0    1   2   3   4   5   6   7   8   9  10
m
0       1
1       1
2       2    2
3       5    4   3
4      15   11   7   9   5
5      52   36  21  26  12  16   7
6     203  135  74  92  38  52  19  66  29  31  11
		

Crossrefs

A093936 Table T(n,k) read by rows which contains in row n and column k the sum of A001055(A036035(n,j)) over all column indices j where A036035(n,j) has k distinct prime factors.

Original entry on oeis.org

1, 2, 2, 3, 4, 5, 5, 16, 11, 15, 7, 28, 47, 36, 52, 11, 79, 156, 166, 135, 203, 15, 134, 408, 588, 667, 566, 877, 22, 328, 1057, 2358, 2517, 2978, 2610, 4140, 30, 536, 3036, 6181, 10726, 11913, 14548, 13082, 21147, 42, 1197, 6826, 21336, 40130, 53690, 61421
Offset: 1

Views

Author

Alford Arnold, May 23 2004

Keywords

Comments

Sequence A050322 calculates factorizations indexed by prime signatures: A001055(A025487) For example, A050322(36) = A001055(A025487(36)) = 74 and A050322(43) = A001055(A024487(43)) = 92.
Note that A093936 can be readily extended by combining appropriate values from A096443. Row sums of A093936 yield A035310 and embedded sequences include A000041, A035098 and A000110. - Alford Arnold, Nov 19 2005

Examples

			a(19) = 166 because A001055(840) + A001055(1260) = 74 + 92.
Row n=4 of A036035 contains 16=2^4, 24=2^3*3, 36=2^2*3^2, 60=2^2*3*5 and 210=2*3*5*7. The 16 has k=1 distinct prime factor; 24 and 36 have k=2 distinct prime factors; 60 has k=3 distinct prime factors; 210 has k=4 distinct prime factors (see A001221).
T(4,1)=A001055(16)=5.
T(4,2)=A001055(24)+A001055(36)=7+9=16.
T(4,3)=A001055(60)=11.
T(4,4)=A001055(210)=15.
Table starts
1;
2, 2;
3, 4, 5;
5, 16, 11, 15;
7, 28, 47, 36, 52;
11, 79, 156, 166, 135, 203;
15, 134, 408, 588, 667, 566, 877;
22, 328, 1057, 2358, 2517, 2978, 2610, 4140;
30, 536, 3036, 6181, 10726, 11913, 14548, 13082, 21147;
42, 1197, 6826, 21336, 40130, 53690, 61421, 76908, 70631, 115975;
...
		

Crossrefs

Programs

  • Maple
    A036035 := proc(n) local pr,L,a ; a := [] ; pr := combinat[partition](n) ; for L in pr do mul(ithprime(i)^op(-i,L),i=1..nops(L)) ; a := [op(a),%] ; od ; RETURN(a) ; end: A001221 := proc(n) local ifacts ; ifacts := ifactors(n)[2] ; nops(ifacts) ; end: listProdRep := proc(n,mincomp) local dvs,resul,f,i,rli ; resul := 0 ; if n = 1 then RETURN(1) elif n >= mincomp then dvs := numtheory[divisors](n) ; for i from 1 to nops(dvs) do f := op(i,dvs) ; if f =n and f >= mincomp then resul := resul+1 ; elif f >= mincomp then rli := listProdRep(n/f,f) ; resul := resul+rli ; fi ; od ; fi ; RETURN(resul) ; end: A001055 := proc(n) listProdRep(n,2) ; end: A093936 := proc(n,k) local a, a036035,j ; a := 0 ; a036035 := A036035(n) ; for j in a036035 do if A001221(j) = k then a := a+A001055(j) ; fi ; od ; RETURN(a) ; end: for n from 1 to 10 do for k from 1 to n do printf("%d,",A093936(n,k)) ; od : od : # R. J. Mathar, Jul 27 2007

Extensions

More terms from Alford Arnold, Nov 19 2005
More terms from R. J. Mathar, Jul 27 2007

A129305 Encodes multisets of least prime signatures in reverse-lex order: replace A036035 with A080688 then calculate all possible factorizations of the resulting values, recode each factor using A064553(n) and then multiply the terms.

Original entry on oeis.org

1, 2, 4, 5, 6, 11, 8, 10, 17, 12, 15, 22, 31, 42, 69, 77, 86, 109, 16, 20, 25, 34, 47, 24, 30, 44, 55, 51, 62, 83, 36, 45, 66, 76, 95, 121, 93, 118, 149, 84, 105, 138, 154, 172, 215, 253, 201, 217, 218, 277, 546, 834, 861, 897, 994, 1001, 1118, 1529, 1633, 1763, 1041
Offset: 0

Views

Author

Alford Arnold, May 02 2007

Keywords

Comments

Sequence A035310 counts the values in each subtable and illustrates relationships with A000041, A000079, A000110 etc. Sequence A096443 counts the values associated with each least prime signature. (Cf. A025487 and A036035.)

Examples

			The encoded values can be arranged in tabular form based on the number of factors and the associated numeric partitions as indicated below:
2..................................................
.....4.....5........................................
.....6.....11........................................
...............8.....10.....17.........................
...............12....15.....31.........................
.....................22..............................
...............42....69.....109.........................
.....................77..............................
.....................86..............................
.................................16.....20.....25.....34.....47
.................................24.....30.....55.....51.....83
........................................44............62.....
.................................36.....45.....95.....93.....149
........................................66.....121...118.....
........................................76...............
.................................84.....105.....215.....201.....277
........................................138.....253.....217.....
........................................154.............218.....
........................................172...............
................................546.....834.....1529.....1041.....1289
........................................861.....1633.....1138.....
........................................897.....1763.....1253.....
........................................994..............1417.....
........................................1001...............
........................................1118...............
		

Crossrefs

A130273 Refines A075197(n): number of partitions of n balls of n colors. The refinement has shape A000041(n).

Original entry on oeis.org

1, 4, 2, 9, 24, 5, 20, 84, 54, 132, 15, 35, 240, 320, 630, 780, 720, 52, 66, 570, 870, 2280, 465, 6240, 4440, 1320, 8280, 4050, 203, 105, 1260, 1974, 6720, 2394, 20580, 19740, 14385, 11445, 83160, 31080, 34860, 77910, 23772, 877, 176, 2520, 4312, 17640, 5432
Offset: 1

Views

Author

Alford Arnold, May 19 2007

Keywords

Comments

a(n) can be calculated by resorting A035206 into Mathematica order vice AS1 ordering and then multiplying term by term with A096443(n).

Examples

			The array begins
1
4 2
9 24 5
20 84 54 132 15
...
Row three is (9,24,5) because there are (3, 4,5) cases; and we have (3, 6,1) ways to pick 1,2 or 3 colors.
		

Crossrefs

Previous Showing 11-14 of 14 results.