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.

Showing 1-10 of 10 results.

A056239 If n = Product_{k >= 1} (p_k)^(c_k) where p_k is k-th prime and c_k >= 0 then a(n) = Sum_{k >= 1} k*c_k.

Original entry on oeis.org

0, 1, 2, 2, 3, 3, 4, 3, 4, 4, 5, 4, 6, 5, 5, 4, 7, 5, 8, 5, 6, 6, 9, 5, 6, 7, 6, 6, 10, 6, 11, 5, 7, 8, 7, 6, 12, 9, 8, 6, 13, 7, 14, 7, 7, 10, 15, 6, 8, 7, 9, 8, 16, 7, 8, 7, 10, 11, 17, 7, 18, 12, 8, 6, 9, 8, 19, 9, 11, 8, 20, 7, 21, 13, 8, 10, 9, 9, 22, 7, 8, 14, 23, 8, 10, 15, 12, 8, 24, 8, 10
Offset: 1

Views

Author

Leroy Quet, Aug 19 2000

Keywords

Comments

A pseudo-logarithmic function in the sense that a(b*c) = a(b)+a(c) and so a(b^c) = c*a(b) and f(n) = k^a(n) is a multiplicative function. [Cf. A248692 for example.] Essentially a function from the positive integers onto the partitions of the nonnegative integers (1->0, 2->1, 3->2, 4->1+1, 5->3, 6->1+2, etc.) so each value a(n) appears A000041(a(n)) times, first with the a(n)-th prime and last with the a(n)-th power of 2. Produces triangular numbers from primorials. - Henry Bottomley, Nov 22 2001
Michael Nyvang writes (May 08 2006) that the Danish composer Karl Aage Rasmussen discovered this sequence in the 1990's: it has excellent musical properties.
All A000041(a(n)) different n's with the same value a(n) are listed in row a(n) of triangle A215366. - Alois P. Heinz, Aug 09 2012
a(n) is the sum of the parts of the partition having Heinz number n. We define the Heinz number of a partition p = [p_1, p_2, ..., p_r] as Product_{j=1..r} (p_j-th prime) (concept used by Alois P. Heinz in A215366 as an "encoding" of a partition). For example, for the partition [1, 1, 2, 4, 10] we get 2*2*3*7*29 = 2436. Example: a(33) = 7 because the partition with Heinz number 33 = 3 * 11 is [2,5]. - Emeric Deutsch, May 19 2015

Examples

			a(12) = 1*2 + 2*1 = 4, since 12 = 2^2 *3^1 = (p_1)^2 *(p_2)^1.
		

Crossrefs

Programs

  • Haskell
    a056239 n = sum $ zipWith (*) (map a049084 $ a027748_row n) (a124010_row n)
    -- Reinhard Zumkeller, Apr 27 2013
    
  • Maple
    # To get 10000 terms. First make prime table: M:=10000; pl:=array(1..M); for i from 1 to M do pl[i]:=0; od: for i from 1 to M do if ithprime(i) > M then break; fi; pl[ithprime(i)]:=i; od:
    # Decode Maple's amazing syntax for factoring integers: g:=proc(n) local e,p,t1,t2,t3,i,j,k; global pl; t1:=ifactor(n); t2:=nops(t1); if t2 = 2 and whattype(t1) <> `*` then p:=op(1,op(1,t1)); e:=op(2,t1); t3:=pl[p]*e; else
    t3:=0; for i from 1 to t2 do j:=op(i,t1); if nops(j) = 1 then e:=1; p:=op(1,j); else e:=op(2,j); p:=op(1,op(1,j)); fi; t3:=t3+pl[p]*e; od: fi; t3; end; # N. J. A. Sloane, May 10 2006
    A056239 := proc(n) add( numtheory[pi](op(1,p))*op(2,p), p = ifactors(n)[2]) ; end proc: # R. J. Mathar, Apr 20 2010
    # alternative:
    with(numtheory): a := proc (n) local B: B := proc (n) local nn, j, m: nn := op(2, ifactors(n)): for j to nops(nn) do m[j] := op(j, nn) end do: [seq(seq(pi(op(1, m[i])), q = 1 .. op(2, m[i])), i = 1 .. nops(nn))] end proc: add(B(n)[i], i = 1 .. nops(B(n))) end proc: seq(a(n), n = 1 .. 130); # Emeric Deutsch, May 19 2015
  • Mathematica
    a[1] = 0; a[2] = 1; a[p_?PrimeQ] := a[p] = PrimePi[p];
    a[n_] := a[n] = Total[#[[2]]*a[#[[1]]] & /@ FactorInteger[n]]; a /@ Range[91] (* Jean-François Alcover, May 19 2011 *)
    Table[Total[FactorInteger[n] /. {p_, c_} /; p > 0 :> PrimePi[p] c], {n, 91}] (* Michael De Vlieger, Jul 12 2017 *)
  • PARI
    A056239(n) = if(1==n,0,my(f=factor(n)); sum(i=1, #f~, f[i,2] * primepi(f[i,1]))); \\ Antti Karttunen, Oct 26 2014, edited Jan 13 2020
    
  • Python
    from sympy import primepi, factorint
    def A056239(n): return sum(primepi(p)*e for p, e in factorint(n).items()) # Chai Wah Wu, Jan 01 2023
  • Scheme
    (require 'factor) ;; Uses the function factor available in Aubrey Jaffer's SLIB Scheme library.
    (define (A056239 n) (apply + (map A049084 (factor n))))
    ;; Antti Karttunen, Oct 26 2014
    

Formula

Totally additive with a(p) = PrimePi(p), where PrimePi(n) = A000720(n).
a(n) = Sum_{k=1..A001221(n)} A049084(A027748(k))*A124010(k). - Reinhard Zumkeller, Apr 27 2013
From Antti Karttunen, Oct 11 2014: (Start)
a(n) = n - A178503(n).
a(n) = A161511(A156552(n)).
a(n) = A227183(A243354(n)).
For all n >= 0:
a(A002110(n)) = A000217(n). [Cf. Henry Bottomley's comment above.]
a(A005940(n+1)) = A161511(n).
a(A243353(n)) = A227183(n).
Also, for all n >= 1:
a(A241909(n)) = A243503(n).
a(A122111(n)) = a(n).
a(A242424(n)) = a(n).
A248692(n) = 2^a(n). (End)
a(n) < A329605(n), a(n) = A001222(A108951(n)), a(A329902(n)) = A112778(n). - Antti Karttunen, Jan 14 2020

A056556 First tetrahedral coordinate; repeat m (m+1)*(m+2)/2 times.

Original entry on oeis.org

0, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
Offset: 0

Views

Author

Henry Bottomley, Jun 26 2000

Keywords

Comments

If {(X,Y,Z)} are triples of nonnegative integers with X >= Y >= Z ordered by X, Y and Z, then X=A056556(n), Y=A056557(n) and Z=A056558(n).
From Gus Wiseman, Jul 03 2019: (Start)
Also the maximum number of distinct multiplicities among integer partitions of n. For example, random partitions of 56 realizing each number of distinct multiplicities are:
1: (24,17,6,5,3,1)
2: (10,9,9,5,5,4,4,3,3,2,1,1)
3: (6,5,5,5,4,4,4,3,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)
4: (28,5,5,3,3,3,2,2,1,1,1,1,1)
5: (13,4,4,4,4,4,3,3,3,2,2,2,2,2,2,1,1)
6: (6,5,5,4,4,4,3,3,3,3,2,2,2,2,2,1,1,1,1,1,1)
The maximum number of distinct multiplicities is 6, so a(56) = 6.
(End)

Examples

			3 is (3+1) * (3+2)/2 = 10 times in the sequence all these occurrences are in consecutive places. The first 3 is at position binomial(3 + 2, 3) = 10, the last one at binomial((3 + 1) + 2, 3) - 1. - _David A. Corneth_, Oct 14 2022
		

Crossrefs

Programs

  • Mathematica
    Table[Table[m, {(m+1)(m+2)/2}], {m, 0, 7}] // Flatten (* Jean-François Alcover, Feb 28 2019 *)
  • PARI
    a(n)=my(t=polrootsreal(x^3+3*x^2+2*x-6*n)); t[#t]\1 \\ Charles R Greathouse IV, Feb 22 2017
    
  • Python
    from math import comb
    from sympy import integer_nthroot
    def A056556(n): return (m:=integer_nthroot(6*(n+1),3)[0])-(nChai Wah Wu, Nov 04 2024

Formula

a(n) = floor(x) where x is the (largest real) solution to x^3 + 3x^2 + 2x - 6n = 0; a(A000292(n)) = n+1.
a(n+1) = a(n)+1 if a(n) = A056558(n), otherwise a(n). - Graeme McRae, Jan 09 2007
a(n) = floor(t/3 + 1/t - 1), where t = (81*n + 3*sqrt(729*n^2 - 3))^(1/3). - Ridouane Oudra, Mar 21 2021
a(n) = floor(t + 1/(3*t) - 1), where t = (6*n)^(1/3), for n>=1. - Ridouane Oudra, Nov 04 2022
a(n) = m if n>=binomial(m+2,3) and a(n) = m-1 otherwise where m = floor((6n+6)^(1/3)). - Chai Wah Wu, Nov 04 2024

Extensions

Incorrect formula deleted by Ridouane Oudra, Nov 04 2022

A325833 Number of integer partitions of n whose number of submultisets is less than n.

Original entry on oeis.org

0, 0, 0, 1, 2, 3, 5, 7, 9, 14, 20, 21, 27, 43, 50, 56, 69, 98, 118, 143, 165, 200, 229, 249, 282, 454, 507, 555, 637, 706, 789, 889, 986, 1406, 1567, 1690, 1875, 2396, 2602, 2841, 3078, 3672, 3977, 4344, 4660, 5079, 5488, 5840, 6296, 10424, 11306
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 A325797.

Examples

			The a(3) = 1 through a(9) = 14 partitions:
  (3)  (4)   (5)   (6)    (7)    (8)     (9)
       (22)  (32)  (33)   (43)   (44)    (54)
             (41)  (42)   (52)   (53)    (63)
                   (51)   (61)   (62)    (72)
                   (222)  (322)  (71)    (81)
                          (331)  (332)   (333)
                          (511)  (422)   (432)
                                 (611)   (441)
                                 (2222)  (522)
                                         (531)
                                         (621)
                                         (711)
                                         (3222)
                                         (6111)
		

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-> add(b(n$2, k), k=0..n-1):
    seq(a(n), n=0..55);  # Alois P. Heinz, Aug 17 2019
  • Mathematica
    Table[Length[Select[IntegerPartitions[n],Times@@(1+Length/@Split[#])Jean-François Alcover, May 12 2021, after Alois P. Heinz *)

Formula

a(n) = A000041(n) - A325832(n).
For n even, a(n) = A325834(n) - A325830(n/2); for n odd, a(n) = A325834(n).

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 *)

A325834 Number of integer partitions of n whose number of submultisets is less than or equal to n.

Original entry on oeis.org

0, 0, 1, 1, 3, 3, 6, 7, 12, 14, 21, 21, 37, 43, 51, 56, 90, 98, 130, 143, 180, 200, 230, 249, 403, 454, 508, 555, 657, 706, 826, 889, 1295, 1406, 1568, 1690, 2194, 2396, 2603, 2841, 3387, 3672, 4024, 4344, 4693, 5079, 5489, 5840, 9731, 10424, 11336, 12093
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 A325798.

Examples

			The a(2) = 1 through a(9) = 14 partitions:
  (2)  (3)  (4)   (5)   (6)    (7)    (8)     (9)
            (22)  (32)  (33)   (43)   (44)    (54)
            (31)  (41)  (42)   (52)   (53)    (63)
                        (51)   (61)   (62)    (72)
                        (222)  (322)  (71)    (81)
                        (411)  (331)  (332)   (333)
                               (511)  (422)   (432)
                                      (431)   (441)
                                      (521)   (522)
                                      (611)   (531)
                                      (2222)  (621)
                                      (5111)  (711)
                                              (3222)
                                              (6111)
		

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-> add(b(n$2, k), k=0..n):
    seq(a(n), n=0..55);  # Alois P. Heinz, Aug 17 2019
  • Mathematica
    Table[Length[Select[IntegerPartitions[n],Times@@(1+Length/@Split[#])<=n&]],{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, Function[w, b[w, Min[w, i - 1], Quotient[p, j + 1]]][n - i*j], 0], {j, 0, n/i}]];
    a[n_] := Sum[b[n, n, k], {k, 0, n}];
    a /@ Range[0, 55] (* Jean-François Alcover, May 10 2021, after Alois P. Heinz *)

Formula

a(n) = A000041(n) - A325831(n).
For n even, A325833(n) = a(n) - A325830(n/2); for n odd, A325833(n) = a(n).

A088881 If A056239(m) = n, then a(n) is the maximum value of A000005(m).

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 10, 12, 16, 20, 24, 30, 36, 42, 48, 60, 72, 84, 96, 112, 128, 144, 168, 192, 224, 256, 288, 336, 384, 432, 480, 540, 600, 672, 768, 864, 960, 1080, 1200, 1320, 1440, 1620, 1800, 1980, 2160, 2400, 2640, 2880, 3240, 3600, 3960, 4320, 4800, 5280
Offset: 0

Views

Author

Naohiro Nomoto, Nov 28 2003

Keywords

Comments

Maximum number of submultisets among all integer partitions of n. - Gus Wiseman, Jun 30 2019

Examples

			The partition (3,2,1,1,1) has 16 submultisets, which is more than for any other partition of 8, so a(8) = 16. - _Gus Wiseman_, Jun 30 2019
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0 or i<2, n+1,
           max(seq((j+1)*b(n-i*j, i-1), j=0..n/i)))
        end:
    a:= n-> b(n, n):
    seq (a(n), n=0..100);  # Alois P. Heinz, Aug 09 2012
  • Mathematica
    $RecursionLimit = 1000; b[n_, i_] :=  b[n, i] = If[n == 0 || i<2, n+1, Max[Table[ (j+1)*b[n-i*j, i-1], {j, 0, n/i}]]]; a[n_] := b[n, n]; Table [a[n], {n, 0, 100}] (* Jean-François Alcover, Apr 15 2015, after Alois P. Heinz *)
    Table[Max@@(Times@@(1+Length/@Split[#])&)/@IntegerPartitions[n],{n,0,30}] (* Gus Wiseman, Jun 30 2019 *)

A307699 Numbers k such that there is no integer partition of k with exactly k-1 submultisets.

Original entry on oeis.org

0, 1, 2, 6, 8, 12, 14, 18, 20, 24, 26, 30, 32, 38, 42, 44, 48, 50, 54, 60, 62, 66, 68, 72, 74, 80, 84, 86, 90, 92, 98, 102, 104, 108, 110, 114, 122, 126, 128, 132, 134, 138, 140, 146, 150, 152, 158, 164, 168, 170, 174, 180, 182, 186, 192, 194, 198, 200, 206
Offset: 1

Views

Author

Gus Wiseman, May 30 2019

Keywords

Comments

After a(1) = 0, first differs from A229488 in lacking 56.
The number of submultisets of a partition is the product of its multiplicities, each plus one.
{a(n)-1} contains all odd numbers m = p*q*... such that gcd(p-1, q-1, ...) > 2. In particular, {a(n)-1} contains all powers of all primes > 3. Proof: If g is the greatest common divisor, then all factors of k are congruent to 1 modulo g, and thus all multiplicities of any valid multiset are divisible by g. However, the required sum is congruent to 2 modulo g, and so no such multiset can exist. - Charlie Neder, Jun 06 2019

Examples

			The sequence of positive terms together with their prime indices begins:
   1: {}
   2: {1}
   6: {1,2}
   8: {1,1,1}
  12: {1,1,2}
  14: {1,4}
  18: {1,2,2}
  20: {1,1,3}
  24: {1,1,1,2}
  26: {1,6}
  30: {1,2,3}
  32: {1,1,1,1,1}
  38: {1,8}
  42: {1,2,4}
  44: {1,1,5}
  48: {1,1,1,1,2}
  50: {1,3,3}
  54: {1,2,2,2}
  60: {1,1,2,3}
Partitions realizing the desired number of submultisets for each non-term are:
   3: (3)
   4: (22)
   5: (41)
   7: (511)
   9: (621)
  10: (4411)
  11: (71111)
  13: (9211)
  15: (9111111)
  16: (661111)
  17: (9521)
  19: (94411)
  21: (981111)
  22: (88111111)
  23: (32222222222)
  25: (99421)
  27: (3222222222222)
  28: (994411)
  29: (98222222)
		

Crossrefs

Programs

  • Mathematica
    Select[Range[50],Function[n,Select[IntegerPartitions[n], Times@@(1+Length/@Split[#])==n-1&]=={}]]

Extensions

More terms from Alois P. Heinz, May 30 2019

A325835 Number of integer partitions of 2*n having one more distinct submultiset than distinct subset-sums.

Original entry on oeis.org

0, 0, 1, 2, 3, 5, 9, 10, 14, 22, 30, 33, 46, 52, 74, 107, 101, 123, 171, 182, 225
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. A subset-sum of an integer partition is the sum of some submultiset of its parts. These are partitions with one subset-sum which is the sum of two distinct submultisets, while all others are the sum of only one submultiset.
The Heinz numbers of these partitions are given by A325802.

Examples

			The a(2) = 1 through a(8) = 14 partitions:
  (211)  (321)   (422)    (532)     (633)      (743)       (844)
         (3111)  (431)    (541)     (642)      (752)       (853)
                 (41111)  (5221)    (651)      (761)       (862)
                          (5311)    (4332)     (7322)      (871)
                          (511111)  (5331)     (7331)      (5443)
                                    (6222)     (7421)      (7441)
                                    (6411)     (7511)      (7531)
                                    (33222)    (72221)     (8332)
                                    (6111111)  (74111)     (8521)
                                               (71111111)  (8611)
                                                           (82222)
                                                           (83311)
                                                           (85111)
                                                           (811111111)
For example, the partition (7,5,3,1) has submultisets (), (1), (3), (5), (7), (3,1), (5,1), (5,3), (7,1), (7,3), (7,5), (5,3,1), (7,3,1), (7,5,1), (7,5,3), (7,5,3,1), all of which have different sums except for (5,3) and (7,1), which both sum to 8, so (7,5,3,1) is counted under a(8).
		

Crossrefs

Programs

  • Mathematica
    Table[Length[Select[IntegerPartitions[n],Times@@(1+Length/@Split[#])==1+Length[Union[Total/@Subsets[#]]]&]],{n,0,20,2}]

A325987 Irregular triangle read by rows where T(n,k) is the number of integer partitions of n with k submultisets, k > 0.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 1, 0, 2, 0, 1, 1, 1, 1, 1, 0, 1, 0, 2, 0, 3, 0, 1, 0, 1, 1, 3, 0, 1, 1, 2, 1, 1, 0, 1, 0, 3, 0, 3, 0, 4, 0, 1, 0, 3, 0, 1, 1, 3, 1, 3, 0, 3, 2, 1, 0, 4, 0, 1, 1, 1, 0, 1, 0, 5, 0, 3, 0, 5, 0, 3, 0, 6, 0, 1, 0, 3, 0, 2, 0, 1, 0, 1, 1, 4, 0
Offset: 0

Views

Author

Gus Wiseman, May 30 2019

Keywords

Comments

The number of submultisets of a partition is the product of its multiplicities, each plus one.

Examples

			Triangle begins:
  1
  0 1
  0 1 1
  0 1 0 2
  0 1 1 1 1 1
  0 1 0 2 0 3 0 1
  0 1 1 3 0 1 1 2 1 1
  0 1 0 3 0 3 0 4 0 1 0 3
  0 1 1 3 1 3 0 3 2 1 0 4 0 1 1 1
  0 1 0 5 0 3 0 5 0 3 0 6 0 1 0 3 0 2 0 1
  0 1 1 4 0 5 0 7 2 1 1 4 0 1 2 5 0 3 0 2 1 0 0 2
Row n = 7 counts the following partitions (empty columns not shown):
  (7)  (43)  (322)  (421)      (31111)  (3211)
       (52)  (331)  (2221)              (22111)
       (61)  (511)  (4111)              (211111)
                    (1111111)
		

Crossrefs

Row lengths are A088881.
Row sums are A000041.
Diagonal n = k is A325830 interspersed with zeros.
Diagonal n + 1 = k is A325828.
Diagonal n - 1 = k is A325836.
Column k = 3 appears to be A137719.

Programs

  • Mathematica
    Table[Length[Select[IntegerPartitions[n],Times@@(1+Length/@Split[#])==k&]],{n,0,10},{k,1,Max@@(Times@@(1+Length/@Split[#])&)/@IntegerPartitions[n]}]

Formula

Sum_{k=1..A088881(n)} k * T(n,k) = A000712(n). - Alois P. Heinz, Aug 17 2019

A140312 Number of distinct values of Product_{p is in P} (m(p,P)+1) where m(p,P) is the multiplicity of part p in partition P, when P ranges over all partitions of n.

Original entry on oeis.org

1, 2, 3, 5, 5, 10, 10, 16, 18, 24, 27, 41, 42, 54, 63, 82, 88, 114, 123, 153, 168, 205, 224, 278, 296, 356, 388, 462, 497, 587, 634, 746, 795, 934, 987, 1159, 1241, 1427, 1521, 1750, 1862, 2120, 2270, 2578, 2726, 3108, 3291, 3723, 3937, 4425, 4686, 5278, 5569, 6208, 6552, 7328, 7720, 8609, 9072
Offset: 1

Views

Author

Vladeta Jovovic, May 25 2008

Keywords

Crossrefs

Programs

  • PARI
    a(n)=my(v=List());forpart(P=n,listput(v,prod(i=1,#P, sum(j=1,#P, P[j]==P[i])+1))); #vecsort(Vec(v),,8) \\ Charles R Greathouse IV, Jun 18 2013

Extensions

More terms from Max Alekseyev, Aug 17 2013
Showing 1-10 of 10 results.