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 22 results. Next

A089504 A generalization of triangle A071951 (Legendre-Stirling).

Original entry on oeis.org

1, 6, 1, 36, 30, 1, 216, 756, 90, 1, 1296, 18360, 6156, 210, 1, 7776, 441936, 387720, 31356, 420, 1, 46656, 10614240, 23705136, 4150440, 119556, 756, 1, 279936, 254788416, 1432922400, 521757936, 29257200, 373572, 1260, 1, 1679616
Offset: 1

Views

Author

Wolfdieter Lang, Dec 01 2003

Keywords

Comments

This triangle underlies the array entry A078741 ((3,3)-generalized Stirling2).
For the computation of the column sequences see A089505.

Examples

			[1]; [6,1]; [36,30,1]; [216,756,90,1]; ...
a(3,2) = 30 = ((-1)*(3*2*1)^1 + 4*(4*3*2)^1)/3.
		

Crossrefs

Cf. A071951 (Legendre-Stirling, (2, 2) case).
The column sequences (without leading zeros) are A000400 (powers of 6), A089507, A089513-4, etc.

Programs

  • Mathematica
    max = 10; f[m_] := 1/Product[1 - FactorialPower[r + 2, 3]*x, {r, 1, m}]; col[m_] := CoefficientList[f[m] + O[x]^(max - m + 1), x]; a[n_, m_] := col[m][[n - m + 1]]; Table[a[n, m], {n, 1, max}, {m, 1, n}] // Flatten (* Jean-François Alcover, Sep 01 2016 *)

Formula

G.f. for m-th column sequence (without leading zeros and m>=1) is 1/Product_{r=1..m} 1-fallfac(r+2, 3)*x with fallfac(n, k) := A008279(n, k) (falling factorials).
a(n, m) = Sum_{p=1..m} A089505(m, p)*((p+2)*(p+1)*p)^(n-m))/D(m) if n>=m>=1 else 0; with D(m) := A089506(m).

A089278 Coefficient triangle for computation of column numbers of triangle A071951 (Legendre-Stirling).

Original entry on oeis.org

1, -1, 3, 1, -15, 24, -7, 405, -2268, 2500, 2, -405, 6048, -20000, 16875, -11, 7425, -266112, 2000000, -4640625, 3176523, 143, -312741, 25474176, -390000000, 1879453125, -3344878719, 1927561216, -143, 995085, -178319232, 5250000000, -46986328125, 163899057231, -236126248960
Offset: 1

Views

Author

Wolfdieter Lang, Nov 07 2003

Keywords

Comments

The k-th column sequence A071951(n+k,k), n>=0, is sum(a(k,p)*(p*(p+1))^n,p=1..k)/A089500(k), k>=1.

Examples

			[1]; [ -1,3]; [1,-15,24]; [ -7,405,-2268,2500]; ...
Sequence A071951(n+3,3)= A016309(n)= [1,20,292,...] has a(n)=
(1*(1*2)^n - 15*(2*3)^n + 24*(3*4)^n)/10.
		

Formula

a(n, m)= A089500(n)*(((-1)^(m+n))*(2*m+1)*((m*(m+1))^n)/((m+n+1)!*(n-m)!)).

A089500 Denominators for computation of column sequences of triangle A071951 (Legendre-Stirling).

Original entry on oeis.org

1, 2, 10, 630, 2520, 277200, 97297200, 3405402000, 463134672000, 475176173472000, 16631166071520000, 4207685016094560000, 3786916514485104000000, 98459829376612704000000
Offset: 1

Views

Author

Wolfdieter Lang, Nov 07 2003

Keywords

Comments

The k-th column sequence A071951(n+k,k), n>=0, is sum(A089278(k,p)*(p*(p+1))^n,p=1..k)/a(k), k>=1.

Formula

a(n)= N(n)/D(n) with N(n) := sfac(n-1)*sfac(2*n+1)/sfac(n+1)= A089501(n) and D(n) := gcd([seq((2*m+1)*((m*(m+1))^n)*N(n)/((n+m+1)!*(n-m)!), m=1..n)]), where sfac(n)=A000178(n) (superfactorials) and gcd(L) is the greatest common divisor >1 of a list of numbers L.

A071952 Diagonal T(n, 4) of triangle in A071951.

Original entry on oeis.org

1, 40, 1092, 25664, 561104, 11807616, 243248704, 4950550528, 100040447232, 2013177300992, 40412056994816, 810023815790592, 16221871691714560, 324694197936160768, 6496965245491888128, 129976281056339296256
Offset: 4

Views

Author

N. J. A. Sloane, Jun 16 2002

Keywords

Crossrefs

Programs

  • GAP
    List([4..20], n-> 2^(n-7)*(20*3^n - 7*6^n + 10^n - 28)/315); # G. C. Greubel, Mar 16 2019
  • Magma
    [2^(n-7)*(20*3^n - 7*6^n + 10^n - 28)/315: n in [4..20]]; // G. C. Greubel, Mar 16 2019
    
  • Mathematica
    Flatten[ Table[ Sum[(-1)^{r + 4}(2r + 1)(r^2 + r)^n/((r + 5)!(4 - r)!), {r, 1, 4}], {n, 4, 20}]]
    LinearRecurrence[{40, -508, 2304, -2880}, {1, 40, 1092, 25664}, 20] (* G. C. Greubel, Mar 16 2019 *)
  • PARI
    {a(n) = 2^(n-7)*(20*3^n - 7*6^n + 10^n - 28)/315}; \\ G. C. Greubel, Mar 16 2019
    
  • Sage
    [2^(n-7)*(20*3^n - 7*6^n + 10^n - 28)/315 for n in (4..20)] # G. C. Greubel, Mar 16 2019
    

Formula

From Wolfdieter Lang, Nov 07 2003: (Start)
a(n+4) = A071951(n+4, 4) = (-7*2^n + 405*6^n - 2268*12^n + 2500*20^n)/630, n >= 0.
G.f.: x^4/((1-2*1*x)*(1-3*2*x)*(1-4*3*x)*(1-5*4*x)). (End)
a(n) = det(|ps(i+2,j+1)|, 1 <= i,j <= n-4), where ps(n,k) are Legendre-Stirling numbers of the first kind (A129467) and n > 3. - Mircea Merca, Apr 06 2013
From G. C. Greubel, Mar 16 2019: (Start)
a(n) = 2^(n-7)*(20*3^n - 7*6^n + 10^n - 28)/315.
E.g.f.: (1 - exp(2*x))^4*(14 + 28*exp(2*x) + 28*exp(4*x) + 20*exp(6*x) + 10*exp(8*x) + 4*exp(10*x) + exp(12*x))/8!. (End)

Extensions

More terms from Robert G. Wilson v, Jun 19 2002
Definition corrected by Georg Fischer, Jul 07 2025

A090215 A generalization of triangles A071951 (Legendre-Stirling) and A089504.

Original entry on oeis.org

1, 24, 1, 576, 144, 1, 13824, 17856, 504, 1, 331776, 2156544, 199296, 1344, 1, 7962624, 259117056, 73903104, 1328256, 3024, 1, 191102976, 31102009344, 26864234496, 1189638144, 6408576, 6048, 1, 4586471424, 3732432224256, 9702226427904, 1026160275456, 11956045824, 24697728, 11088, 1
Offset: 1

Views

Author

Wolfdieter Lang, Dec 01 2003

Keywords

Comments

This triangle underlies the array entry A090214 ((4,4)-generalized Stirling2).

Examples

			[1]; [24,1]; [576,144,1]; [13824,17856,504,1]; ...
		

Crossrefs

Cf. A071951 (Legendre-Stirling, (2, 2) case), A089504 ((3, 3)-case).
The column sequences (without leading zeros) are A009968 (powers of 24), etc.

Programs

  • Mathematica
    max = 10; f[m_] := 1/Product[1-FactorialPower[r+3, 4]*x, {r, 1, m}]; col[m_] := CoefficientList[f[m] + O[x]^(max-m+1), x]; a[n_, m_] := col[m][[n-m+1]]; Table[a[n, m], {n, 1, max}, {m, 1, n}] // Flatten (* Jean-François Alcover, Sep 01 2016 *)

Formula

G.f. for m-th column sequence (without leading zeros and m>=1) is 1/product(1-fallfac(r+3, 4)*x, r=1..m) with fallfac(n, k) := A008279(n, k) (falling factorials).
a(n, m) = sum(A089515(m, p)*fallfac(p, 4)^(n-m), p=1..m)/D(m) if n>=m>=1 else 0; with D(m) := A089516(m).

Extensions

More terms coming from a-file added by Michel Marcus, Feb 08 2023

A089274 Fifth column of the Legendre-Stirling triangle A071951.

Original entry on oeis.org

1, 70, 3192, 121424, 4203824, 137922336, 4380918784, 136378114048, 4191383868672, 127754693361152, 3873052857829376, 117001609550671872, 3526270158211870720, 106112798944292282368, 3189880933574260359168
Offset: 0

Views

Author

Wolfdieter Lang, Nov 07 2003

Keywords

Comments

This is the fifth member of the family A000079 (powers of 2), A016129, A016309, A071952, etc.

Crossrefs

Cf. A000079 (powers of 2).

Programs

  • Magma
    [(16875*(6*5)^n - 20000*(5*4)^n + 6048*(4*3)^n - 405*(3*2)^n + 2*(2*1)^n)/2520: n in [0..20]]; // Vincenzo Librandi, Sep 02 2011
    
  • Mathematica
    Table[2^(n-3)*(5*(15)^(n+3) -2*(10)^(n+4) +28*6^(n+3) -5*3^(n+4) +2)/315, {n,0,30}] (* G. C. Greubel, Nov 10 2024 *)
  • SageMath
    def A089274(n): return 2^n*(5*(15)^(n+3) -2*(10)^(n+4) +28*6^(n+3) -5*3^(n+4) +2)//2520
    [A089274(n) for n in range(31)] # G. C. Greubel, Nov 10 2024

Formula

G.f.: 1/((1-2*1*x)*(1-3*2*x)*(1-4*3*x)*(1-5*4*x)*(1-6*5*x)).
a(n) = (16875*(6*5)^n -20000*(5*4)^n +6048*(4*3)^n -405*(3*2)^n +2*(2*1)^n)/2520.
a(n) = A071951(n+5, 5), n>=0.
a(n) = det(|ps(i+5,j+4)|, 1 <= i,j <= n), where ps(n,k) are Legendre-Stirling numbers of the first kind (A129467). [Mircea Merca, Apr 06 2013]
E.g.f.: (1/2520)*(2*exp(2*x) - 405*exp(6*x) + 6048*exp(12*x) - 20000*exp(20*x) + 16875*exp(30*x)). - G. C. Greubel, Nov 10 2024

A090217 A generalization of triangle A071951 (Legendre-Stirling).

Original entry on oeis.org

1, 120, 1, 14400, 840, 1, 1728000, 619200, 3360, 1, 207360000, 447552000, 9086400, 10080, 1, 24883200000, 322444800000, 23345280000, 76824000, 25200, 1, 2985984000000, 232185139200000, 59152550400000, 539602560000, 457848000
Offset: 1

Views

Author

Wolfdieter Lang, Dec 01 2003

Keywords

Comments

This is the fourth member of the family A071951 (Legendre-Stirling,(2,2) case), A089504((3,3)-case), A090215 ((4,4)-case).
This triangle underlies the array entry A090216 ((5,5)-generalized Stirling2).

Examples

			Triangle starts:
[1];
[120,1];
[14400,840,1];
[1728000,619200,3360,1];
...
		

Crossrefs

The column sequences (without leading zeros) are powers of 120, etc.

Programs

  • Mathematica
    max = 10; f[m_] := 1/Product[1 - FactorialPower[r + 4, 5]*x, {r, 1, m}]; col[m_] := CoefficientList[f[m] + O[x]^(max - m + 1), x]; a[n_, m_] := col[m][[n - m + 1]]; Table[a[n, m], {n, 1, max}, {m, 1, n}] // Flatten (* Jean-François Alcover, Sep 02 2016 *)

Formula

G.f. for m-th column (without leading zeros and m>=1) is 1/product(1-fallfac(r+4, 5)*x, r=1..m) with fallfac(n, k) := A008279(n, k) (falling factorials).
a(n, m)=sum(A090435(m, p)*fallfac(p, 5)^(n-m), p=1..m)/D(m) if n>=m>=1 else 0; with D(m) := A090436(m).

A071953 Diagonal T(n,n-2) of triangle in A071951.

Original entry on oeis.org

4, 52, 292, 1092, 3192, 7896, 17304, 34584, 64284, 112684, 188188, 301756, 467376, 702576, 1028976, 1472880, 2065908, 2845668, 3856468, 5150068, 6786472, 8834760, 11373960, 14493960, 18296460, 22895964, 28420812, 35014252
Offset: 3

Views

Author

N. J. A. Sloane, Jun 16 2002

Keywords

Crossrefs

Programs

  • GAP
    List([3..30], n-> (n-2)*(n-1)*n*(n+1)*(5*n^2 - 11*n + 3)/90); # G. C. Greubel, Mar 16 2019
  • Magma
    [(n-2)*(n-1)*n*(n+1)*(5*n^2 - 11*n + 3)/90: n in [3..30]]; // G. C. Greubel, Mar 16 2019
    
  • Mathematica
    Flatten[ Table[ Sum[(-1)^{r + n - 2}(2r + 1)(r^2 + r)^n/((r + n - 1)!(n - 2 - r)!), {r, 1, n - 2}], {n, 3, 34}]]
    Table[(n-2)(n-1)n(n+1)(5n^2-11n+3)/90,{n,3,30}] (* or *) LinearRecurrence[ {7,-21,35,-35,21,-7,1},{4,52,292,1092,3192, 7896,17304}, 30] (* Harvey P. Dale, Jul 03 2011 *)
  • PARI
    {a(n) = (n-2)*(n-1)*n*(n+1)*(5*n^2 - 11*n + 3)/90}; \\ G. C. Greubel, Mar 16 2019
    
  • Sage
    [(n-2)*(n-1)*n*(n+1)*(5*n^2 - 11*n + 3)/90 for n in (3..30)] # G. C. Greubel, Mar 16 2019
    

Formula

a(n) = (n-2)*(n-1)*n*(n+1)*(5*n^2 - 11*n + 3)/90.
a(0)=4, a(1)=52, a(2)=292, a(3)=1092, a(4)=3192, a(5)=7896, a(6)=17304, a(n)=7*a(n-1)-21*a(n-2)+35*a(n-3)-35*a(n-4)+21*a(n-5)-7*a(n-6)+a(n-7). - Harvey P. Dale, Jul 03 2011
G.f.: 4*(3*x*(x+2)+1)/(1-x)^7. - Harvey P. Dale, Jul 03 2011
E.g.f.: x^3*(60 + 135*x + 54*x^2 + 5*x^3)*exp(x)/90. - G. C. Greubel, Mar 16 2019

Extensions

More terms from Robert G. Wilson v, Jun 19 2002

A089277 Sixth column of the triangle A071951 (Legendre-Stirling).

Original entry on oeis.org

1, 112, 7896, 453056, 23232176, 1113673728, 51155215360, 2284897159168, 100157064553728, 4334351404617728, 185915811851773952, 7925465707325177856, 336395829865869340672, 14234737653310804590592
Offset: 0

Views

Author

Wolfdieter Lang, Nov 07 2003

Keywords

Crossrefs

Formula

G.f.: 1/Product_{p=1..6} (1 - p*(p+1)*x) = 1/((1-2*x)*(1-6*x)*(1-12*x)*(1-20*x)*(1-30*x)*(1-42*x)).
a(n) = A071951(n+6, 6), n>=0.
a(n) = (Sum_{p=1..6} A089278(6, p)*(p*(p+1))^n)/A089500(6) = (-11*2^n + 7425*6^n - 266112*12^n + 2000000*20^n - 4640625*30^n + 3176523*42^n)/277200.
a(n) = det(|ps(i+6,j+5)|, 1 <= i,j <= n), where ps(n,k) are Legendre-Stirling numbers of the first kind (A129467). - Mircea Merca, Apr 06 2013

A372343 a(n) is the permanent of the n X n matrix whose element (i,j) equals PS(i+2,j), where PS(r,c) is the Legendre-Stirling number of the second kind (A071951).

Original entry on oeis.org

1, 12, 2448, 2900160, 3335369728, 16355507060736, 202873109257748480, 5520786912662854893568, 304515605038514679874846720, 31568014831906551177163996921856, 5785425274398818300907155436515360768, 1783302045417843100606023721285336961122304, 886715046570481808433485979311322483302619676672
Offset: 0

Views

Author

Stefano Spezia, Apr 28 2024

Keywords

Crossrefs

Cf. A069135 (determinant), A071951.

Programs

  • Mathematica
    PS[n_,k_]:=Sum[(-1)^(r+k)(2r+1)(r^2+r)^n/((r+k+1)!(k-r)!),{r,0,k}]; a[0]:=1; a[n_]:=Permanent[Table[PS[i+2,j],{i,n},{j,n}]]; Array[a,13,0]
Showing 1-10 of 22 results. Next