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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A137854 Triangle generated from an array: A008277 * A008277(transform).

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 4, 4, 1, 1, 8, 11, 8, 1, 1, 16, 28, 28, 16, 1, 1, 32, 71, 87, 71, 32, 1, 1, 64, 184, 266, 266, 184, 64, 1, 1, 128, 491, 823, 952, 823, 491, 128, 1, 1, 256, 1348, 2598, 3381, 381, 2598, 1348, 2561
Offset: 1

Views

Author

Gary W. Adamson, Feb 15 2008

Keywords

Comments

Row sums = A000995 such that row 1 = A000995(3) = 1.
This array is the product of the lower triangular Stirling matrix and its transpose, which explains why the array is symmetric. - David Callan, Dec 02 2011
In the triangle, T(n,k) is the number of permutations of [n+1] that avoid both dashed patterns 1-23 and 3-12, start with an ascent, and have first entry k. For example, T(4,2)=4 counts 23154, 24153, 24315, 25431. - David Callan, Dec 02 2011

Examples

			First few rows of the array:
  1,  1,  1,   1,   1,    1, ...
  1,  2,  4,   8,  16,   32, ...
  1,  4, 11,  28,  71,  184, ...
  1,  8, 28,  87, 266,  823, ...
  1, 16, 71, 266, 952, 3381, ...
  ...
First few rows of the triangle:
  1;
  1,   1;
  1,   2,   1;
  1,   4,   4,   1;
  1,   8,  11,   8,   1;
  1,  16,  28,  28,  16,   1;
  1,  32,  71,  87,  71,  32,   1;
  1,  64, 184, 266, 266, 184,  64,   1;
  1, 128, 491, 823, 952, 823, 491, 128,   1;
  ...
		

Crossrefs

Formula

Triangle read by rows = antidiagonals of an array formed by A008277 * A008277(transform), where A008277 = the Stirling number of the second kind triangle.

A154959 Triangle read by rows. Signed version of A008277.

Original entry on oeis.org

1, -1, 1, -1, -3, 1, -1, -7, -6, 1, -1, -15, -25, -10, 1, -1, -31, -90, -65, -15, 1, -1, -63, -301, -350, -140, -21, 1, -1, -127, -966, -1701, -1050, -266, -28, 1, -1, -255, -3025, -7770, -6951, -2646, -462, -36, 1
Offset: 1

Views

Author

Mats Granvik, Jan 18 2009

Keywords

Comments

Main diagonal positive, the rest of the terms negative. Matrix inverse of this triangle is A154960. Signs in columns as in A153881.

A223512 Triangle T(n,k) represents the coefficients of (x^10*d/dx)^n, where n=1,2,3,...;generalization of Stirling numbers of second kind A008277, Lah-numbers A008297.

Original entry on oeis.org

1, 10, 1, 190, 30, 1, 5320, 1060, 60, 1, 196840, 45600, 3400, 100, 1, 9054640, 2340040, 208800, 8300, 150, 1, 498005200, 140096880, 14241640, 690200, 17150, 210, 1, 31872332800, 9604302400, 1080045120, 60485040, 1856400, 31640, 280, 1, 2326680294400
Offset: 1

Views

Author

Udita Katugampola, Mar 23 2013

Keywords

Examples

			1;
10,1;
190,30,1;
5320,1060,60,1;
196840,45600,3400,100,1;
9054640,2340040,208800,8300,150,1;
498005200,140096880,14241640,690200,17150,210,1;
31872332800,9604302400,1080045120,60485040,1856400,31640,280,1,2326680294400
		

Crossrefs

Programs

  • Maple
    b[0]:=g(x):
    for j from 1 to 10 do
    b[j]:=simplify(x^10*diff(b[j-1],x$1);
    end do;

A381160 a(n) is the permanent of the n X n matrix whose element (i,j) is equal to A008277(i+3, j) with 1 <= i,j <= n.

Original entry on oeis.org

1, 1, 22, 3206, 1902936, 3504528354, 16660734321540, 179059038168086056, 3938830136216956996632, 164125096331945477980176920, 12173562237817299484378342192768, 1527294306324982018922212102518520032, 310564445230567070838152555220146533261496, 98712056006032672983172826864304778359411112064
Offset: 0

Views

Author

Stefano Spezia, Feb 15 2025

Keywords

Examples

			a(3) = 3206:
  [1,  7,  6]
  [1, 15, 25]
  [1, 31, 90]
		

Crossrefs

Cf. A000442 (determinant), A008277, A381166.

Programs

  • Mathematica
    a[n_]:=Permanent[Table[StirlingS2[i+3,j],{i,n},{j,n}]]; Join[{1},Array[a,13]]
  • PARI
    a(n) = matpermanent(matrix(n, n, i, j, stirling(i+3,j,2))); \\ Michel Marcus, Feb 16 2025

A381166 a(n) is the permanent of the n X n matrix whose element (i,j) is equal to A008277(i+4, j) with 1 <= i,j <= n.

Original entry on oeis.org

1, 1, 46, 23216, 70437736, 911400637082, 39931366088759328, 5015203546888139970264, 1592320463242701429692077472, 1158339311156769223634640734447744, 1783702957209729441902140461938160455424, 5447268928199100257603373050876725987854119216, 31237114830378466799129128930824084710690680271414364
Offset: 0

Views

Author

Stefano Spezia, Feb 15 2025

Keywords

Examples

			a(3) = 23216:
  [1, 15,  25]
  [1, 31,  90]
  [1, 63, 301]
		

Crossrefs

Cf. A008277, A134375 (determinant), A381160.

Programs

  • Mathematica
    a[n_]:=Permanent[Table[StirlingS2[i+4, j], {i, n}, {j, n}]]; Join[{1}, Array[a, 12]]
  • PARI
    a(n) = matpermanent(matrix(n, n, i, j, stirling(i+4,j,2))); \\ Michel Marcus, Feb 16 2025

A166280 Stirling2 triangle mod 2, T(n,k) = A008277(n,k) mod 2.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1
Offset: 0

Views

Author

Gerald McGarvey, Oct 10 2009

Keywords

Examples

			Triangle begins:
1,
1,1,
1,1,1,
1,1,0,1,
1,1,1,0,1,
1,1,0,1,1,1,
1,1,1,0,0,1,1,
1,1,0,1,0,0,0,1,
1,1,1,0,1,0,0,0,1,
1,1,0,1,1,1,0,0,1,1,
1,1,1,0,0,1,1,0,1,1,1,
1,1,0,1,0,0,0,1,1,1,0,1,
1,1,1,0,1,0,0,0,0,1,1,0,1,
...
		

Crossrefs

Cf. A008277, A047999 (Sierpinski's triangle, Pascal's triangle mod 2).

Programs

  • PARI
    p = 2; s=14; S2T = matrix(s,s,n,k, if(k==1,1)); for(n=2,s,for(k=2,n, S2T[n,k]=k*S2T[n-1,k]+S2T[n-1,k-1]));
    S2TMP = matrix(s,s,n,k, S2T[n,k]%p);
    for(n=1,s,for(k=1,n,print1(S2TMP[n,k]," "));print())

A187556 Triangle read by rows of products of (signless) Stirling numbers of the first kind (A132393) and Stirling numbers of the second kind (A008277).

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 2, 9, 1, 0, 6, 77, 36, 1, 0, 24, 750, 875, 100, 1, 0, 120, 8494, 20250, 5525, 225, 1, 0, 720, 111132, 488824, 257250, 24500, 441, 1, 0, 5040, 1659636, 12685512, 11514069, 2058000, 85652, 784, 1, 0, 40320, 27943920, 357325100, 522796680, 156042999, 12002256, 252252, 1296, 1, 0, 362880, 524580336, 10941291000, 24681106400, 11453045625, 1444332771, 55566000, 652500, 2025, 1
Offset: 0

Views

Author

Emanuele Munarini, Mar 11 2011

Keywords

Examples

			Triangle begins:
1
0,1
0,1,1
0,2,9,1
0,6,77,36,1
0,24,750,875,100,1
0,120,8494,20250,5525,225,1
0,720,111132,488824,257250,24500,441,1
0,5040,1659636,12685512,11514069,2058000,85652,784,1
		

Crossrefs

Programs

  • Maple
    seq(seq(abs(combinat[stirling1](n,k))*combinat[stirling2](n,k),k=0..n),n=0..8);
  • Mathematica
    Flatten[Table[Table[Abs[StirlingS1[n, k]]*StirlingS2[n, k], {k, 0, n}],{n, 0, 8}] ,1]
  • Maxima
    create_list(abs(stirling1(n,k)*stirling2(n,k)),n,0,10,k,0,n);

Formula

Formula: a(n,k) = s(n,k)*S(n,k), where the s(n,k) are the (signless) Stirling numbers of the first kind and the S(n,k) are the Stirling numbers of the second kind.

A187557 Triangle read by rows of products of Stirling numbers of the second kind (A008277): a(n,k) = S(n,k) S(n+1,k+1).

Original entry on oeis.org

1, 0, 1, 0, 3, 1, 0, 7, 18, 1, 0, 15, 175, 60, 1, 0, 31, 1350, 1625, 150, 1, 0, 63, 9331, 31500, 9100, 315, 1, 0, 127, 60858, 512001, 367500, 37240, 588, 1, 0, 255, 384175, 7505820, 11823651, 2778300, 122892, 1008, 1, 0, 511, 2379150, 103167625, 330419250, 158670477, 15558480, 346500, 1620, 1, 0, 1023, 14564011, 1359847500, 8414726650, 7632684675, 1460631249, 69854400, 866250, 2475, 1
Offset: 0

Views

Author

Emanuele Munarini, Mar 11 2011

Keywords

Examples

			Triangle begins:
1
0,1
0,3,1
0,7,18,1
0,15,175,60,1
0,31,1350,1625,150,1
0,63,9331,31500,9100,315,1
0,127,60858,512001,367500,37240,588,1
0,255,384175,7505820,11823651,2778300,122892,1008,1
		

Crossrefs

Programs

  • Maple
    seq(seq(combinat[stirling2](n,k)*combinat[stirling2](n+1,k+1),k=0..n),n=0..8);
  • Mathematica
    Table[StirlingS2[n, k]StirlingS2[n + 1, k + 1], {n, 0, 8}, {k, 0, 8}]//MatrixForm
  • Maxima
    create_list(stirling2(n,k)*stirling2(n+1,k+1),n,0,10,k,0,n);

A223514 Triangle T(n,k) represents the coefficients of (x^12*d/dx)^n, where n=1,2,3,...; generalization of Stirling numbers of second kind A008277, Lah-numbers A008297.

Original entry on oeis.org

1, 12, 1, 276, 36, 1, 9384, 1536, 72, 1, 422280, 80040, 4920, 120, 1, 23647680, 4984560, 365400, 12000, 180, 1, 1584394560, 362597760, 30197160, 1205400, 24780, 252, 1, 123582775680, 30229617600, 2778370560, 127834560, 3237360, 45696, 336, 1, 1099867035520
Offset: 1

Views

Author

Udita Katugampola, Mar 23 2013

Keywords

Examples

			1;
12,1;
276,36,1;
9384,1536,72,1;
422280,80040,4920,120,1;
23647680,4984560,365400,12000,180,1;
1584394560,362597760,30197160,1205400,24780,252,1;
123582775680,30229617600,2778370560,127834560,3237360,45696,336,1;
1099867035520,...
		

Crossrefs

Programs

  • Maple
    b[0]:=f(x):
    for j from 1 to 10 do
    b[j]:=simplify(x^12*diff(b[j-1],x$1);
    end do;

A223515 Triangle T(n,k) represents the coefficients of (x^13*d/dx)^n, where n=1,2,3,...; generalization of Stirling numbers of second kind A008277, Lah-numbers A008297.

Original entry on oeis.org

1, 13, 1, 325, 39, 1, 12025, 1807, 78, 1, 589225, 102375, 5785, 130, 1, 35942725, 6936475, 466830, 14105, 195, 1, 2623818925, 549241875, 41948725, 1538810, 29120, 273, 1, 223024608625, 49858620175, 4198780950, 177364005, 4130490, 53690, 364, 1, 21633387036625
Offset: 1

Views

Author

Udita Katugampola, Mar 23 2013

Keywords

Examples

			1;
13,1;
325,39,1;
12025,1807,78,1;
589225,102375,5785,130,1;
35942725,6936475,466830,14105,195,1
2623818925,549241875,41948725,1538810,29120,273,1;
223024608625,49858620175,4198780950,177364005,4130490,53690,364,1;
21633387036625,...
		

Crossrefs

Programs

  • Maple
    b[0]:=f(x):
    for j from 1 to 10 do
    b[j]:=simplify(x^13*diff(b[j-1],x$1);
    end do;
Previous Showing 31-40 of 644 results. Next