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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A135228 Triangle A000012(signed) * A007318 * A103451, read by rows.

Original entry on oeis.org

1, 1, 1, 3, 1, 1, 5, 2, 2, 1, 11, 2, 4, 3, 1, 21, 3, 6, 7, 4, 1, 43, 3, 9, 13, 11, 5, 1, 85, 4, 12, 22, 24, 16, 6, 1, 171, 4, 16, 34, 46, 40, 22, 7, 1, 341, 5, 20, 50, 80, 86, 62, 29, 8, 1, 683, 5, 25, 70, 130, 166, 148, 91, 37, 9, 1, 1365, 6, 30, 95, 200, 296, 314, 239, 128, 46, 10, 1
Offset: 0

Views

Author

Gary W. Adamson, Nov 23 2007

Keywords

Comments

Row sums = A000975: (1, 2, 5, 10, 21, 42, 85, 170, ...).
Left border = A001045: (1, 1, 3, 5, 11, 21, 43, ...).

Examples

			First few rows of the triangle are:
    1;
    1, 1;
    3, 1,  1;
    5, 2,  2,  1;
   11, 2,  4,  3,  1;
   21, 3,  6,  7,  4,  1;
   43, 3,  9, 13, 11,  5,  1;
   85, 4, 12, 22, 24, 16,  6, 1;
  171, 4, 16, 34, 46, 40, 22, 7, 1;
...
		

Crossrefs

Programs

  • Magma
    function T(n,k)
      if k eq 0 then return (2^(n+1) +(-1)^n)/3;
      else return (&+[Binomial(n-2*j-1, k-1): j in [0..Floor((n-1)/2)]]);
      end if; return T; end function;
    [T(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Nov 20 2019
    
  • Maple
    T:= proc(n, k) option remember;
          if k=0 then (2^(n+1) +(-1)^n)/3
        else add(binomial(n-2*j-1, k-1), j=0..floor((n-1)/2))
          fi; end:
    seq(seq(T(n, k), k=0..n), n=0..12); # G. C. Greubel, Nov 20 2019
  • Mathematica
    T[n_, k_]:= T[n, k]= If[k==0, (2^(n+1) +(-1)^n)/3, Sum[Binomial[n-1-2*j, k-1], {j,0,Floor[(n-1)/2]}]]; Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Nov 20 2019 *)
  • PARI
    T(n,k) = if(k==0, (2^(n+1) +(-1)^n)/3, sum(j=0, (n-1)\2, binomial( n-2*j-1, k-1)) ); \\ G. C. Greubel, Nov 20 2019
    
  • Sage
    @CachedFunction
    def T(n, k):
        if (k==0): return (2^(n+1) +(-1)^n)/3
        else: return sum(binomial(n-2*j-1, k-1) for j in (0..floor((n-1)/2)))
    [[T(n, k) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Nov 20 2019

Formula

T(n,k) = A000012(signed) * A007318 * A103451 as infinite lower triangular matrices. A000012(signed) = (1; -1,1; 1,-1,1; ...).
T(n,k) = Sum_{j=0..floor((n-1)/2)} binomial(n-2*j-1, k-1), with T(n,0) =
(2^(n+1) - (-1)^(n+1))/3 (Jacobsthal_{n+1}).- G. C. Greubel, Nov 20 2019

Extensions

Offset changed by G. C. Greubel, Nov 20 2019

A135229 Triangle A000012(signed) * A103451 * A007318, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 4, 3, 1, 1, 3, 6, 7, 4, 1, 1, 3, 9, 13, 11, 5, 1, 1, 4, 12, 22, 24, 16, 6, 1, 1, 4, 16, 34, 46, 40, 22, 7, 1, 1, 5, 20, 50, 80, 86, 62, 29, 8, 1
Offset: 0

Views

Author

Gary W. Adamson, Nov 23 2007

Keywords

Comments

row sums = A005578 starting (1, 2, 3, 6, 11, 22, 43, 86, ...).

Examples

			First few rows of the triangle are:
  1;
  1, 1;
  1, 1,  1;
  1, 2,  2,  1;
  1, 2,  4,  3,  1;
  1, 3,  6,  7,  4,  1;
  1, 3,  9, 13, 11,  5,  1;
  1, 4, 12, 22, 24, 16,  6, 1;
  1, 4, 16, 34, 46, 40, 22, 7, 1;
...
		

Crossrefs

Programs

  • Magma
    function T(n,k)
      if k eq 0 then return 1;
      else return (&+[Binomial(n-2*j-1, k-1): j in [0..Floor((n-1)/2)]]);
      end if; return T; end function;
    [T(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Nov 20 2019
    
  • Maple
    T:= proc(n, k) option remember;
          if k=0 then 1
        else add(binomial(n-2*j-1, k-1), j=0..floor((n-1)/2))
          fi; end:
    seq(seq(T(n, k), k=0..n), n=0..12); # G. C. Greubel, Nov 20 2019
  • Mathematica
    T[n_, k_]:= T[n, k]= If[k==0, 1, Sum[Binomial[n-1-2*j, k-1], {j, 0, Floor[(n-1)/2]}]]; Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Nov 20 2019 *)
  • PARI
    T(n,k) = if(k==0, 1, sum(j=0, (n-1)\2, binomial( n-2*j-1, k-1)) ); \\ G. C. Greubel, Nov 20 2019
    
  • Sage
    @CachedFunction
    def T(n, k):
        if (k==0): 1
        else: return sum(binomial(n-2*j-1, k-1) for j in (0..floor((n-1)/2)))
    [[T(n, k) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Nov 20 2019

Formula

T(n,k) = A000012(signed) * A103451 * A007318 as infinite lower triangular matrices, where A000012(signed) = (1; -1,1; 1,-1,1; ...).
T(n,k) = Sum_{j=0..floor((n-1)/2)} binomial(n-2*j-1, k-1), with T(n,0) = 1. - G. C. Greubel, Nov 20 2019

Extensions

Offset changed by G. C. Greubel, Nov 20 2019

A135230 Triangle A103451 * A000012(signed) * A007318, read by rows.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 2, 2, 4, 3, 1, 1, 3, 6, 7, 4, 1, 2, 3, 9, 13, 11, 5, 1, 1, 4, 12, 22, 24, 16, 6, 1, 2, 4, 16, 34, 46, 40, 22, 7, 1, 1, 5, 20, 50, 80, 86, 62, 29, 8, 1, 2, 5, 25, 70, 130, 166, 148, 91, 37, 9, 1, 1, 6, 30, 95, 200, 296, 314, 239, 128, 46, 10, 1
Offset: 0

Views

Author

Gary W. Adamson, Nov 23 2007

Keywords

Comments

row sums = A135231

Examples

			First few rows of the triangle are:
  1;
  1, 1;
  2, 1,  1;
  1, 2,  2,  1;
  2, 2,  4,  3,  1;
  1, 3,  6,  7,  4,  1;
  2, 3,  9, 13, 11,  5,  1;
  1, 4, 12, 22, 24, 16,  6, 1;
  2, 4, 16, 34, 46, 40, 22, 7, 1;
...
		

Crossrefs

Programs

  • Magma
    function T(n,k)
      if k eq n then return 1;
      elif k eq 0 then return (3+(-1)^n)/2;
      else return (&+[Binomial(n-2*j-1, k-1): j in [0..Floor((n-1)/2)]]);
      end if; return T; end function;
    [T(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Nov 20 2019
    
  • Maple
    T:= proc(n, k) option remember;
          if k=n then 1
        elif k=0 then (3+(-1)^n)/2
        else add(binomial(n-2*j-1, k-1), j=0..floor((n-1)/2))
          fi; end:
    seq(seq(T(n, k), k=0..n), n=0..12); # G. C. Greubel, Nov 20 2019
  • Mathematica
    T[n_, k_]:= T[n, k]= If[k==n, 1, If[k==0, (3+(-1)^n)/2, Sum[Binomial[n-1 - 2*j, k-1], {j, 0, Floor[(n-1)/2]}] ]]; Table[T[n, k], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Nov 20 2019 *)
  • PARI
    T(n,k) = if(k==n, 1, if(k==0, (3+(-1)^n)/2, sum(j=0, (n-1)\2, binomial( n-2*j-1, k-1)) )); \\ G. C. Greubel, Nov 20 2019
    
  • Sage
    @CachedFunction
    def T(n, k):
        if (k==n): return 1
        elif (k==0): return (3+(-1)^n)/2
        else: return sum(binomial(n-2*j-1, k-1) for j in (0..floor((n-1)/2)))
    [[T(n, k) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Nov 20 2019

Formula

T(n,k) = A103451 * A000012(signed) * A007318, where A000012(signed) = (1; -1,1; 1,-1,1;...).
T(n,k) = Sum_{j=0..floor((n-1)/2)} binomial(n-2*j-1, k-1), with T(n,0) = (3+(-1)^n)/2 and T(n,n) = 1. - G. C. Greubel, Nov 20 2019

Extensions

More terms and offset changed by G. C. Greubel, Nov 20 2019

A135723 A122890 + A000012 - I, I = Identity matrix.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 2, 5, 1, 1, 1, 11, 14, 1, 1, 1, 9, 71, 42, 1, 1, 1, 5, 161, 425, 132, 1, 1, 1, 2, 251, 1979, 2383, 429, 1, 1, 1, 1, 303, 6277, 19509, 12805, 1430, 1, 1, 1, 1, 299, 15675, 106493, 168609, 66947, 4862
Offset: 0

Views

Author

Gary W. Adamson, Nov 25 2007

Keywords

Comments

Row sums = A005095: (1, 2, 4, 9, 28, 125, 726, ...).
Main diagonal = A000108, the Catalan numbers: (1, 1, 2, 5, 14, 42, 132, ...).

Examples

			First few rows of the triangle:
  1;
  1, 1;
  1, 1, 2;
  1, 1, 2,  5;
  1, 1, 1, 11,  14;
  1, 1, 1,  9,  71,   42;
  1, 1, 1,  5, 161,  425,  132;
  1, 1, 1,  2, 251, 1979, 2383, 429;
  ...
		

Crossrefs

Formula

A122890 + A000012 - Identity matrix; as infinite lower triangular matrices.

A135840 A135839 * A000012 as infinite lower triangular matrices.

Original entry on oeis.org

1, 2, 1, 2, 1, 1, 3, 2, 1, 1, 3, 2, 2, 1, 1, 4, 3, 2, 2, 1, 1, 4, 3, 3, 2, 2, 1, 1, 5, 4, 3, 3, 2, 2, 1, 1, 5, 4, 4, 3, 3, 2, 2, 1, 1, 6, 5, 4, 4, 3, 3, 2, 2, 1, 1, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 7, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 7, 6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 8, 7, 6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1
Offset: 1

Views

Author

Gary W. Adamson, Dec 01 2007

Keywords

Comments

Row sums = A004652 starting (1, 3, 4, 7, 9, 13, 16, 21, ...).

Examples

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

Crossrefs

Programs

  • Mathematica
    T[1, 1] := 1; T[n_, 1] := Floor[(n + 2)/2]; T[n_, n_] := 1; T[n_, k_] := Floor[(n - k + 2)/2]; Table[T[n, k], {n, 1, 8}, {k, 1, n}]//Flatten (* G. C. Greubel, Dec 05 2016 *)

Formula

T(1, 1) = 1, T(n, 1) = floor((n + 2)/2), T(n, n) = 1, T(n, k) = floor((n - k + 2)/2). - G. C. Greubel, Dec 05 2016

A136536 Triangle read by rows: A001263 * A128064 * A000012 as infinite lower triangular matrices.

Original entry on oeis.org

1, 2, 2, 5, 7, 3, 14, 19, 19, 4, 42, 51, 71, 41, 5, 132, 146, 216, 216, 76, 6, 429, 449, 617, 827, 547, 127, 7, 1430, 1457, 1793, 2675, 2675, 1205, 197, 8, 4862, 4897, 5497, 8017, 10369, 7429, 2389, 289, 9, 16796, 16840, 17830, 23770, 34858, 34858, 18226, 4366, 406, 10
Offset: 1

Views

Author

Gary W. Adamson, Jan 04 2008

Keywords

Comments

Row sums = A001791: (1, 4, 15, 56, 210, 792, ...).
Left column = A000108 starting (1, 2, 5, 14, 42, 132, 429, ...).

Examples

			First few rows of the triangle:
    1;
    2,   2;
    5,   7,   3;
   14,  19,  19,   4;
   42,  51,  71,  41,   5;
  132, 146, 216, 216,  76,   6;
  429, 449, 617, 827, 547, 127,   7;
  ...
		

Crossrefs

Extensions

a(46) = 16796 corrected and two more terms from Georg Fischer, May 31 2023

A136787 Triangle read by rows: A107131 * A000012.

Original entry on oeis.org

1, 1, 1, 2, 2, 1, 4, 4, 4, 1, 9, 9, 9, 7, 1, 21, 21, 21, 21, 11, 1, 51, 51, 51, 51, 46, 16, 1, 127, 127, 127, 127, 127, 92, 22, 1, 323, 323, 323, 323, 323, 309, 169, 29, 1, 835, 835, 835, 835, 835, 835, 709, 289, 37, 1
Offset: 1

Views

Author

Gary W. Adamson, Jan 21 2008

Keywords

Comments

Row sums = A005773 starting (1, 2, 5, 13, 35, 96, 267, ...).
Leftmost column = A001006: (1, 1, 2, 4, 9, 21, 51, ...).

Examples

			First few rows of the triangle:
    1;
    1,   1;
    2,   2,   1;
    4,   4,   4,   1;
    9,   9,   9,   7,   1;
   21,  21,  21,  21,  11,  1;
   51,  51,  51,  51,  46, 16,  1;
  127, 127, 127, 127, 127, 92, 22, 1;
  ...
		

Crossrefs

Formula

A107131 * A000012 as infinite lower triangular matrices.

A136788 Triangle read by rows: A000012 * A107131.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 2, 4, 1, 1, 2, 6, 7, 1, 1, 2, 6, 17, 11, 1, 1, 2, 6, 22, 41, 16, 1, 1, 2, 6, 22, 76, 86, 22, 1, 1, 2, 6, 22, 90, 226, 162, 29, 1, 1, 2, 6, 22, 90, 352, 582, 281, 37, 1
Offset: 0

Views

Author

Gary W. Adamson, Jan 21 2008

Keywords

Comments

Row sums = A086615: (1, 2, 4, 8, 17, 38, ...).

Examples

			First few rows of the triangle:
  1;
  1, 1;
  1, 2, 1;
  1, 2, 4,  1;
  1, 2, 6,  7,  1;
  1, 2, 6, 17, 11,  1;
  1, 2, 6, 22, 41, 16,  1;
  1, 2, 6, 22, 76, 86, 22, 1;
  ...
		

Crossrefs

Formula

A000012 * A107131 as infinite lower triangular matrices.

A137593 Triangle read by rows: matrix product A000012 * A136717.

Original entry on oeis.org

1, 1, 2, 1, 4, 4, 1, 4, 16, 12, 1, 4, 16, 84, 48, 1, 4, 16, 156, 504, 192, 1, 4, 16, 156, 1464, 3312, 960, 1, 4, 16, 156, 1464, 14112, 24720, 5760, 1, 4, 16, 156, 1464, 24912, 158640, 189360, 34560, 1, 4, 16, 156, 1464, 24912, 400560, 1761840, 1607040, 241920
Offset: 1

Views

Author

Gary W. Adamson, Jan 28 2008

Keywords

Comments

Right border = A004527: (1, 2, 4, 12, 48, 192, ...).
Row sums = A007489 starting (1, 3, 9, 33, 153, ...).

Examples

			First few rows of the triangle:
  1;
  1, 2;
  1, 4,  4;
  1, 4, 16,  12;
  1, 4, 16,  84,   48;
  1, 4, 16, 156,  504,  192;
  1, 4, 16, 156, 1464, 3312, 960;
  ...
		

Crossrefs

Formula

A000012 * A136717 as infinite lower triangular matrices.

Extensions

Typo in eighth row corrected by Olivier Gérard, Oct 30 2012

A137633 Triangle read by rows, A000012 * A026794.

Original entry on oeis.org

1, 2, 1, 4, 1, 1, 7, 2, 1, 1, 12, 3, 1, 1, 1, 19, 5, 2, 1, 1, 1, 30, 7, 3, 1, 1, 1, 1, 45, 11, 4, 2, 1, 1, 1, 1, 67, 15, 6, 3, 1, 1, 1, 1, 1, 97, 22, 8, 4, 2, 1, 1, 1, 1, 1, 139, 30, 11, 5, 3, 1, 1, 1, 1, 1, 1
Offset: 1

Views

Author

Gary W. Adamson, Jan 31 2008

Keywords

Comments

Left border = A000070: (1, 2, 4, 7, 12, 19, 30, 45, ...).
Second column = A000041, the partition numbers: (1, 1, 2, 3, 5, 7, 11, ...).
Row sums = A016905: (1, 3, 6, 11, 18, 29, 44, ...).

Examples

			First few rows of the triangle:
   1;
   2, 1;
   4, 1, 1;
   7, 2, 1, 1;
  12, 3, 1, 1, 1;
  19, 5, 2, 1, 1, 1;
  30, 7, 3, 1, 1, 1, 1;
  ...
		

Crossrefs

Formula

A000012 * A026794 as infinite lower triangular matrices.
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