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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A208058 Triangle by rows relating to the factorials, generated from A002260.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 2, 4, 3, 1, 6, 12, 9, 4, 1, 24, 48, 36, 16, 5, 1, 120, 240, 180, 80, 25, 6, 1, 720, 1440, 1080, 480, 150, 36, 7, 1, 5040, 10080, 7560, 3360, 1050, 252, 49, 8, 1, 40320, 80640, 60480, 26880, 8400, 2016, 392, 64, 9, 1
Offset: 0

Views

Author

Gary W. Adamson, Feb 22 2012

Keywords

Comments

Row sums = A054091: (1, 2, 4, 10, 32, 130, 652,...)
Left border = the factorials, A000142 prefaced with a 1.

Examples

			First few rows of the triangle =
1;
1, 1;
1, 2, 1;
2, 4, 3, 1;
6, 12, 9, 4, 1;
24, 48, 36, 16, 5, 1;
120, 240, 180, 80, 25, 6, 1;
720, 1440, 1080, 480, 150, 36, 7, 1;
5040, 10080, 7560, 3360, 1050, 252, 49, 8, 1;
...
		

Crossrefs

Programs

  • Maple
    T:= proc(n) option remember; local M, k;
          M:= Matrix(n+1, (i, j)->
                     `if`(i=j, 1, `if`(i>j, j*(-1)^(i+j), 0)))^(-1);
          seq(M[n+1, k], k=1..n+1)
        end:
    seq(T(n), n=0..14);  # Alois P. Heinz, Feb 24 2012
  • Mathematica
    T[n_] := T[n] = Module[{M}, M = Table[If[i == j, 1, If[i>j, j*(-1)^(i+j), 0]], {i, 1, n+1}, {j, 1, n+1}] // Inverse; M[[n+1]]]; Table[T[n], {n, 0, 14}] // Flatten (* Jean-François Alcover, Mar 09 2015, after Alois P. Heinz *)

Formula

Inverse of:
1;
-1, 1;
1, -2, 1;
-1, 2, -3, 1;
1, -2, 3, -4, 1;
..., where triangle A002260 = (1; 1,2; 1,2,3;...)

A127718 A007318 * A002260 as infinite lower triangular matrices; A002260 = [1; 1,2; 1,2,3; ...].

Original entry on oeis.org

1, 2, 2, 4, 6, 3, 8, 14, 12, 4, 16, 30, 33, 20, 5, 32, 62, 78, 64, 30, 6, 64, 126, 171, 168, 110, 42, 7, 128, 254, 360, 396, 320, 174, 56, 8, 256, 510, 741, 876, 815, 558, 259, 72, 9, 512, 1022, 1506, 1864, 1910, 1536, 910, 368, 90, 10, 1024, 2046, 3039, 3872, 4240
Offset: 1

Views

Author

Gary W. Adamson, Jan 25 2007

Keywords

Comments

Binomial transform of A002260.
Row sums = A084851: (1, 4, 13, 38, 104, 272, ...) A002260 * A007318 = A127717.

Examples

			First few rows of the triangle:
   1;
   2,   2;
   4,   6,   3;
   8,  14,  12,   4;
  16,  30,  33,  20,   5;
  32,  62,  78,  64,  30,  6;
  64, 126, 171, 168, 110, 42, 7;
  ...
		

Crossrefs

Programs

  • Maple
    A007318 := proc(n,k) binomial(n,k) ; end: A002260 := proc(n,k) if k <= n then k; else 0 ; fi ; end: A127718 := proc(n,k) add( A007318(n-1,i-1)*A002260(i,k),i=1..n) ; end: for n from 1 to 15 do for k from 1 to n do printf("%d,",A127718(n,k)) ; od: od: # R. J. Mathar, Oct 02 2007

Formula

T(n,k) = Sum_{i=1..n} A007318(n-1,i-1)*A002260(i,k). - R. J. Mathar, Oct 02 2007

Extensions

More terms from R. J. Mathar, Oct 02 2007

A127735 Triangle read by rows: A127701 * A002260 as infinite lower triangular matrices.

Original entry on oeis.org

1, 3, 4, 4, 8, 9, 5, 10, 15, 16, 6, 12, 18, 24, 25, 7, 14, 21, 28, 35, 36, 8, 16, 24, 32, 40, 48, 49, 9, 18, 27, 36, 45, 54, 63, 64, 10, 20, 30, 40, 50, 60, 70, 80, 81, 11, 22, 33, 44, 55, 66, 77, 88, 99, 100, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 121, 13, 26, 39, 52, 65, 78, 91, 104, 117, 130, 143, 144
Offset: 1

Views

Author

Gary W. Adamson, Jan 26 2007

Keywords

Examples

			First few rows of the triangle are:
1;
3, 4;
4, 8, 9;
5, 10, 15, 16;
6, 12, 18, 24, 25;
...
		

Crossrefs

Formula

Row sums = A127736: (1, 7, 21, 46, 85, 141, ...).
T(n,n) = n^2. T(n,k) = k*(n+1), 1<=kR. J. Mathar, Jul 21 2009

Extensions

A-number of left factor in the definition corrected by R. J. Mathar, Jul 21 2009
a(19) corrected and more terms from Georg Fischer, Jun 05 2023

A128078 A002260 * A128064.

Original entry on oeis.org

1, -1, 4, -1, -2, 9, -1, -2, -3, 16, -1, -2, -3, -4, 25, -1, -2, -3, -4, -5, 36, -1, -2, -3, -4, -5, -6, 49, -1, -2, -3, -4, -5, -6, -7, 64
Offset: 1

Views

Author

Gary W. Adamson, Feb 14 2007

Keywords

Comments

Row sums = the triangular numbers: (1, 3, 6, 10, ...).
Row sums of A128077 = A000326, the pentagonal numbers: (1, 5, 12, 22, 35, ...).

Examples

			First few rows of the triangle:
   1;
  -1,  4;
  -1, -2,  9;
  -1, -2, -3, 16;
  ...
		

Crossrefs

Formula

A002260 * A128064 as infinite lower triangular matrices. Retain the right border of A128077 and change the signs of all other terms to (-).

A130124 Triangle defined by A130123 * A002260, read by rows.

Original entry on oeis.org

1, 2, 4, 4, 8, 12, 8, 16, 24, 32, 16, 32, 48, 64, 80, 32, 64, 96, 128, 160, 192, 64, 128, 192, 256, 320, 384, 448, 128, 256, 384, 512, 640, 768, 896, 1024, 256, 512, 768, 1024, 1280, 1536, 1792, 2048, 2304, 512, 1024, 1536, 2048, 2560, 3072, 3584, 4096, 4608, 5120
Offset: 1

Views

Author

Gary W. Adamson, May 11 2007

Keywords

Comments

Row sums = A001780, (1, 6, 24, 80, 240, ...).

Examples

			First few rows of the triangle are:
   1;
   2,  4;
   4,  8, 12;
   8, 16, 24,  32;
  16, 32, 48,  64,  80;
  32, 64, 96, 128, 160, 192; ...
		

Crossrefs

Programs

  • GAP
    Flat(List([1..12], n-> List([1..n], k-> 2^(n-1)*k ))); # G. C. Greubel, Jun 05 2019
  • Magma
    [[2^(n-1)*k: k in [1..n]]: n in [1..12]]; // G. C. Greubel, Jun 05 2019
    
  • Mathematica
    Table[2^(n-1)*k, {n,1,12}, {k,1,n}]//Flatten (* G. C. Greubel, Jun 05 2019 *)
  • PARI
    {T(n,k) = 2^(n-1)*k}; \\ G. C. Greubel, Jun 05 2019
    
  • Sage
    [[2^(n-1)*k for k in (1..n)] for n in (1..12)] # G. C. Greubel, Jun 05 2019
    

Formula

A130123 * A002260, where A130123 = the 2^n transform and A002260 = [1; 1, 2; 1, 2, 3; ...).
T(n, k) = 2^(n-1)*k. - G. C. Greubel, Jun 05 2019

Extensions

More terms added by G. C. Greubel, Jun 05 2019

A131416 (A000012 * A002260) + (A002260 * A000012) - A000012.

Original entry on oeis.org

1, 4, 3, 8, 8, 5, 13, 14, 12, 7, 19, 21, 20, 16, 9, 26, 29, 29, 26, 20, 11, 34, 38, 39, 37, 32, 24, 13, 43, 48, 50, 49, 45, 38, 28, 15, 53, 59, 62, 62, 59, 53, 44, 32, 17, 64, 71, 75, 76, 74, 69, 61, 50, 36, 19
Offset: 1

Views

Author

Gary W. Adamson, Jul 08 2007

Keywords

Comments

Left column = A034856: (1, 4, 8, 13, 19, 26, 34,...). Row sums = A127735: (1, 7, 21, 46, 85...).

Examples

			First few rows of the triangle are:
1;
4, 3;
8, 8, 5;
13, 14, 12, 7;
19, 21, 20, 16, 9;
26, 29, 29, 26, 20, 11;
...
		

Crossrefs

Formula

(A000012 * A002260) + (A002260 * A000012) - A000012; as infinite lower triangular matrices.

A133091 A133080 * A002260.

Original entry on oeis.org

1, 2, 2, 1, 2, 3, 2, 4, 6, 4, 1, 2, 3, 4, 5, 2, 4, 6, 8, 10, 6, 1, 2, 3, 4, 5, 6, 7, 2, 4, 6, 8, 10, 12, 14, 8, 1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 4, 6, 8, 10, 12, 14, 16, 18, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2
Offset: 1

Views

Author

Gary W. Adamson, Sep 09 2007

Keywords

Comments

Row sums = A133092: (1, 4, 6, 16, 15, 36, 28, ...).

Examples

			First few rows of the triangle:
  1;
  2,  2;
  1,  2,  3;
  2,  4,  6,  4;
  1,  2,  3,  4,  5;
  2,  4,  6,  8, 10,  6;
  1,  2,  3,  4,  5,  6,  7;
  ...
		

Crossrefs

Programs

  • Mathematica
    T[n_, n_] := n; T[n_, k_] := (2 - (1 - (-1)^n)/2)*k; Table[T[n, k], {n, 1, 10}, {k, 1, n}] (* G. C. Greubel, Oct 21 2017 *)
  • PARI
    for(n=1,10, for(k=1,n, print1(if(k==n, n,(2 - (1 - (-1)^n)/2)*k), ", "))) \\ G. C. Greubel, Oct 21 2017

Formula

A133080 * A002260 as infinite lower triangular matrices.
Odd n rows = (1,2,3,...,n). Even n rows = (2,4,6,...,n).

Extensions

Corrected and extended by Philippe Deléham, Mar 02 2012

A134446 A128174 * A002260.

Original entry on oeis.org

1, 1, 2, 2, 2, 3, 2, 4, 3, 4, 3, 4, 6, 4, 5, 3, 6, 6, 8, 5, 6, 4, 6, 9, 8, 10, 6, 7, 4, 8, 9, 12, 10, 12, 7, 8, 5, 8, 12, 12, 15, 12, 14, 8, 9, 5, 10, 12, 16, 15, 18, 14, 16, 9, 10
Offset: 1

Views

Author

Gary W. Adamson, Oct 25 2007

Keywords

Comments

Row sums = A002623: (1, 3, 7, 13, 22, 34, ...).

Examples

			First few rows of the triangle:
  1;
  1,  2;
  2,  2,  3;
  2,  4,  3,  4;
  3,  4,  6,  4,  5;
  3,  6,  6,  8,  5,  6;
  4,  6,  9,  8, 10,  6,  7;
  ...
		

Crossrefs

Formula

A128174 * A002260 as infinite lower triangular matrices.

A134836 Antidiagonals of the array: A007318 * A002260(transposed).

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 5, 3, 1, 1, 7, 8, 3, 1, 1, 9, 16, 8, 3, 1, 1, 11, 27, 20, 8, 3, 1, 1, 13, 41, 43, 20, 8, 3, 1, 1, 15, 58, 81, 48, 20, 8, 3, 1, 1, 17, 78, 138, 106, 48, 20, 8, 3, 1, 1, 19, 101, 218, 213, 112, 48, 20, 8, 3, 1
Offset: 1

Views

Author

Gary W. Adamson, Nov 12 2007

Keywords

Comments

Antidiagonals tend to A001792 starting from the right: (1, 3, 8, 20, 48, 112, ...).

Examples

			First few rows of the array:
  1,  1,  1,  1,   1,   1, ...;
  1,  3,  3,  3,   3,   3, ...;
  1,  5,  8,  8,   8,   8, ...;
  1,  7, 16, 20,  20,  20, ...;
  1,  9, 27, 43,  48,  48, ...;
  1, 11, 41, 81, 106, 112, ...;
  ...
First few rows of the triangle:
  1;
  1,  1;
  1,  3,  1;
  1,  5,  3,  1;
  1,  7,  8,  3,  1;
  1,  9, 16,  8,  3,  1;
  1, 11, 27, 20,  8,  3,  1;
  1, 13, 41, 43, 20,  8,  3,  1;
  ...
		

Crossrefs

Cf. A002260, A001792, A116445 (array transposed), A001629 (antidiagonal sums).

Programs

  • Maple
    A002260 := proc(n,k)
        if n <= k then
            n+1;
        else
            0 ;
        end if;
    end proc:
    A007318 := proc(n,k)
        if k <= n then
            binomial(n,k) ;
        else
            0
        end if;
    end proc:
    A134836 := proc(n,k)
        add( A007318(n,i)*A002260(i,k),i=0..k) ;
    end proc:
    seq(seq(A134836(d-k,k),k=0..d),d=0..12) ; # R. J. Mathar, Aug 17 2022

Formula

Antidiagonals of the array: A007318 * A002260(transform), where A002260 = (1; 1,2; 1,2,3; ...).

Extensions

One term corrected by R. J. Mathar, Aug 17 2022

A134868 A103451 * A002260.

Original entry on oeis.org

1, 2, 2, 2, 2, 3, 2, 2, 3, 4, 2, 2, 3, 4, 5, 2, 2, 3, 4, 5, 6, 2, 2, 3, 4, 5, 6, 7, 2, 2, 3, 4, 5, 6, 7, 8, 2, 2, 3, 4, 5, 6, 7, 8, 9, 2, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 2, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
Offset: 1

Views

Author

Gary W. Adamson, Nov 14 2007

Keywords

Comments

Row sums = A134869: (1, 4, 7, 11, 16, 22, 29, ...).

Examples

			First few rows of the triangle:
  1;
  2, 2;
  2, 2, 3;
  2, 2, 3, 4;
  2, 2, 3, 4, 5;
  ...
		

Crossrefs

Programs

  • Mathematica
    Table[k + Boole[k == 1 && n != 2], {n, 2, 14}, {k, n - 1}] // Flatten (* Michael De Vlieger, Jul 19 2016 *)

Formula

A103451 * A002260 as infinite lower triangular matrices.
Left border of A002260, (1, 1, 1, 1, ...) is replaced by (1, 2, 2, 2, ...).
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