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 1-7 of 7 results.

A144895 Second column of triangle A134134 (S2'(2) = S1hat(2)).

Original entry on oeis.org

1, 2, 10, 36, 204, 1104, 7776, 57600, 505440, 4803840, 51442560, 597784320, 7609593600, 104364288000, 1541746483200, 24329797632000, 409042632499200, 7290954768384000, 137384159367168000, 2727604332085248000, 56913717580296192000, 1244955414746824704000
Offset: 0

Views

Author

Wolfdieter Lang, Oct 09 2008

Keywords

Comments

Sum of the products of the factorials of the partition parts of n+2 into two parts. - Wesley Ivan Hurt, Mar 18 2016

Examples

			a(2)=10; The partitions of (2)+2 = 4 into two parts are: (3,1) and (2,2). The sum of the products of the factorials of the partition parts is: 3!*1! + 2!*2! = 6 + 4 = 10. - _Wesley Ivan Hurt_, Mar 18 2016
		

Crossrefs

Cf. A000142 (factorials, first column). A144896 (third column).
Cf. A134134.

Programs

Formula

a(n) = A134134(n+2,2), n>=0.
a(n) = Sum_{i=1..floor(n/2)+1} i! * (n-i+2)!. - Wesley Ivan Hurt, Mar 18 2016

A134135 Alternating row sums of triangle A134134.

Original entry on oeis.org

1, 1, 5, 15, 93, 551, 4129, 33607, 312929, 3179343, 35602881, 432201743, 5678740945, 80142780751, 1210609725905, 19481112885231, 332836223507793, 6016678424942063, 114746996449871761, 2302527084416470255
Offset: 1

Views

Author

Wolfdieter Lang Oct 12 2007

Keywords

Comments

Difference of numbers sum(product(j!^e(n,m,k,j),j=1..n),k=1..p(n,m)) related to odd and even part m partitions of n. Here e(n,m,k,j) is the exponent of j in the k-th m part partition of n and p(n,m)=A008284(n,m) is the number of partitions of n with m parts.

Crossrefs

Cf. A077365 (row sums of A134134).

Formula

a(n)=sum(A134134(n,m)*(-1)^(m-1),m=1..n),n>=1.

A144896 Third column of triangle A134134 (S2'(2)= S1hat(2)).

Original entry on oeis.org

1, 2, 10, 44, 228, 1272, 8760, 63936, 547776, 5145984, 54233280, 624291840, 7879472640, 107423677440, 1579212910080, 24832164556800, 416273901926400, 7403098797158400, 139238590721126400, 2760253302701260800, 57522218527420416000, 1256931901812400128000
Offset: 0

Views

Author

Wolfdieter Lang, Oct 09 2008

Keywords

Crossrefs

Cf. A134134, A000142 (factorials, first column). A144895 (second column).

Formula

a(n) = A134134(n+3,3), n>=0.

A077365 Sum of products of factorials of parts in all partitions of n.

Original entry on oeis.org

1, 1, 3, 9, 37, 169, 981, 6429, 49669, 430861, 4208925, 45345165, 536229373, 6884917597, 95473049469, 1420609412637, 22580588347741, 381713065286173, 6837950790434781, 129378941557961565, 2578133190722896861, 53965646957320869469, 1183822028149936497501
Offset: 0

Views

Author

Vladeta Jovovic, Nov 30 2002

Keywords

Comments

Row sums of arrays A069123 and A134133. Row sums of triangle A134134.

Examples

			The partitions of 4 are 4, 3+1, 2+2, 2+1+1, 1+1+1+1, the corresponding products of factorials of parts are 24,6,4,2,1 and their sum is a(4) = 37.
1 + x + 3 x^2 + 9 x^3 + 37 x^4 + 169 x^5 + 981 x^6 + 6429 x^7 + 49669 x^8 + ...
		

Crossrefs

Cf. A051296 (with compositions instead of partitions).

Programs

  • Maple
    b:= proc(n, i, j) option remember;
          `if`(n=0, 1, `if`(i<1, 0, b(n, i-1, j)+
          `if`(i>n, 0, j^i*b(n-i, i, j+1))))
        end:
    a:= n-> b(n$2, 1):
    seq(a(n), n=0..40);  # Alois P. Heinz, Aug 03 2013
    # second Maple program:
    b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
           b(n, i-1)+`if`(i>n, 0, b(n-i, i)*i!)))
        end:
    a:= n-> b(n$2):
    seq(a(n), n=0..30);  # Alois P. Heinz, May 11 2016
  • Mathematica
    Table[Plus @@ Map[Times @@ (#!) &, IntegerPartitions[n]], {n, 0, 20}] (* Olivier Gérard, Oct 22 2011 *)
    a[ n_] := If[ n < 0, 0, Plus @@ Times @@@ (IntegerPartitions[ n] !)] (* Michael Somos, Feb 09 2012 *)
    nmax=20; CoefficientList[Series[Product[1/(1-k!*x^k),{k,1,nmax}],{x,0,nmax}],x] (* Vaclav Kotesovec, Mar 14 2015 *)
    b[n_, i_, j_] := b[n, i, j] = If[n==0, 1, If[i<1, 0, b[n, i-1, j] + If[i>n, 0, j^i*b[n-i, i, j+1]]]]; a[n_] := b[n, n, 1]; Table[a[n], {n, 0, 40}] (* Jean-François Alcover, Oct 12 2015, after Alois P. Heinz *)
  • PARI
    N=66; q='q+O('q^N);
    gf= 1/prod(n=1,N, (1-n!*q^n) );
    Vec(gf)
    /* Joerg Arndt, Oct 06 2012 */

Formula

G.f.: 1/Product_{m>0} (1-m!*x^m).
Recurrence: a(n) = 1/n*Sum_{k=1..n} b(k)*a(n-k), where b(k) = Sum_{d divides k} d*d!^(k/d).
a(n) ~ n! * (1 + 1/n + 3/n^2 + 12/n^3 + 67/n^4 + 457/n^5 + 3734/n^6 + 35741/n^7 + 392875/n^8 + 4886114/n^9 + 67924417/n^10), for coefficients see A256125. - Vaclav Kotesovec, Mar 14 2015
G.f.: exp(Sum_{k>=1} Sum_{j>=1} (j!)^k*x^(j*k)/k). - Ilya Gutkovskiy, Jun 18 2018

Extensions

Unnecessarily complicated mma code deleted by N. J. A. Sloane, Sep 21 2009

A134133 A certain partition array in Abramowitz-Stegun order (A-St order).

Original entry on oeis.org

1, 2, 1, 6, 2, 1, 24, 6, 4, 2, 1, 120, 24, 12, 6, 4, 2, 1, 720, 120, 48, 36, 24, 12, 8, 6, 4, 2, 1, 5040, 720, 240, 144, 120, 48, 36, 24, 24, 12, 8, 6, 4, 2, 1, 40320, 5040, 1440, 720, 576, 720, 240, 144, 96, 72, 120, 48, 36, 24, 16, 24, 12, 8, 6, 4, 2, 1, 362880, 40320, 10080
Offset: 1

Views

Author

Wolfdieter Lang, Oct 12 2007

Keywords

Comments

The sequence of row lengths is A000041 (partition numbers) [1, 2, 3, 5, 7, 11, 15, 22, 30, 42,...].
Partition number array M_3(2)= A130561 divided by partition number array M_3 = M_3(1) = A036040.

Examples

			[1], [2,1], [6,2,1], [24,6,4,2,1], [120,24,12,6,4,2,1], ...
		

Crossrefs

With another ordering of the partitions this becomes A069123.
Cf. A134134 (triangle obtained by summing same m numbers).

Formula

a(n,k) = A130561(n,k)/A036040(n,k) (division of partition arrays M_3(2) by M_3).
a(n,k) = product(j!^e(n,k,j),j=1..n) with the exponent e(n,k,j) of j in the k-th partition of n in the A-St ordering of the partitions of n.

A134146 Triangle of numbers obtained from the partition array A134145.

Original entry on oeis.org

1, 3, 1, 15, 3, 1, 105, 24, 3, 1, 945, 150, 24, 3, 1, 10395, 1485, 177, 24, 3, 1, 135135, 14805, 1620, 177, 24, 3, 1, 2027025, 191520, 16425, 1701, 177, 24, 3, 1, 34459425, 2687580, 208125, 16830, 1701, 177, 24, 3, 1, 654729075, 44552025, 2880360, 212985
Offset: 1

Views

Author

Wolfdieter Lang, Nov 13 2007

Keywords

Comments

This triangle is named S2(3)'.
In the same manner the unsigned Lah triangle A008297 is obtained from the partition array A130561.

Examples

			[1]; [3,1]; [15,3,1]; [105,24,3,1]; [945,150,24,3,1];...
		

Crossrefs

Cf. A134147 (row sums).
Cf. A134148 (allternating row sums).
Cf. A134134 (k=2 member of this triangle family).

Formula

a(n,m)=sum(product(S2(3;j,1)^e(n,m,q,j),j=1..n),q=1..p(n,m)) if n>=m>=1, else 0. Here p(n,m)=A008284(n,m), the number of m parts partitions of n and e(n,m,q,j) is the exponent of j in the q-th m part partition of n. S2(3;j,1)= A001147(j) = A035342(j,1) = (2*j-1)!!.

A144351 Lower triangular array called S1hat(1) related to partition number array A107106.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 6, 3, 1, 1, 24, 8, 3, 1, 1, 120, 34, 9, 3, 1, 1, 720, 156, 36, 9, 3, 1, 1, 5040, 924, 166, 37, 9, 3, 1, 1, 40320, 6144, 968, 168, 37, 9, 3, 1, 1, 362880, 48096, 6372, 978, 169, 37, 9, 3, 1, 1, 3628800, 420480, 49368, 6416, 980, 169, 37, 9, 3, 1, 1, 39916800, 4134240
Offset: 1

Views

Author

Wolfdieter Lang Oct 09 2008

Keywords

Comments

If in the partition array M31hat(1):=A107106 entries with the same parts number m are summed one obtains this triangle of numbers S1hat(1). In the same way the signless Stirling1 triangle |A008275| is obtained from the partition array M_2 = A036039.
The first three columns are A000142(n-1) (factorials), A024419 (guess), A144352.

Examples

			[1];[1,1];[2,1,1];[6,3,1,1];[24,8,3,1,1];...
		

Crossrefs

Row sums A107107.
A134134 (S1hat(2)= S2'(2)).

Formula

a(n,m)=sum(product(|S1(1;j,1)|^e(n,m,q,j),j=1..n),q=1..p(n,m)) if n>=m>=1, else 0. Here p(n,m)=A008284(n,m), the number of m parts partitions of n and e(n,m,q,j) is the exponent of j in the q-th m part partition of n. |S1(1,n,1)|= |A008275(n,1)| = A000142(n-1) = (n-1)!.
Showing 1-7 of 7 results.