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.

Previous Showing 61-70 of 2634 results. Next

A134249 Triangle read by rows, taken from the lower triangular matrix (M * A000012 + A000012 * M) - A000012; where M = lower triangular matrix with (1,1,1,...) in the main diagonal and the triangular numbers in the subdiagonal and A000012 = (1; 1,1; 1,1,1; ...).

Original entry on oeis.org

1, 3, 1, 5, 7, 1, 8, 10, 13, 1, 12, 14, 17, 21, 1, 17, 19, 22, 26, 31, 1, 23, 25, 28, 32, 37, 43, 1, 30, 32, 35, 39, 44, 50, 57, 1, 38, 40, 43, 47, 52, 58, 65, 73, 1, 47, 49, 52, 56, 61, 67, 74, 82, 91, 1
Offset: 1

Views

Author

Gary W. Adamson, Oct 15 2007

Keywords

Comments

Row sums = A037235: (1, 4, 13, 32, 65, 116, ...). Left column = A134250: (1, 3, 5, 8, 12, 17, 23, ...).

Examples

			First few rows of the triangle:
   1;
   3,  1;
   5,  7,  1;
   8, 10, 13,  1;
  12, 14, 17, 21,  1;
  17, 19, 22, 26, 31,  1;
  23, 25, 28, 32, 37, 43,  1;
  ...
		

Crossrefs

Extensions

Edited by N. J. A. Sloane, Nov 01 2009

A134310 (A000012 * A134309 + A134309 * A000012) - A000012, where the sequences are interpreted as lower triangular matrices.

Original entry on oeis.org

1, 1, 1, 2, 2, 3, 4, 4, 5, 7, 8, 8, 9, 11, 15, 16, 16, 17, 19, 23, 31, 32, 32, 33, 35, 39, 47, 63, 64, 64, 65, 67, 71, 79, 95, 127, 128, 128, 129, 131, 135, 143, 159, 191, 255, 256, 256, 257, 259, 263, 271, 287, 319, 383, 511
Offset: 0

Views

Author

Gary W. Adamson, Oct 19 2007

Keywords

Comments

From M. F. Hasler, Mar 29 2022: (Start)
Both A000012 and A134309 have offset 0, so this triangular matrix also has row and column indices starting at 0.
Right (resp. left) multiplication by a diagonal matrix (such as A134309) amounts to multiplying the columns (resp. rows) of the other matrix by the diagonal elements. Therefore this matrix is the sum of the two lower triangular matrices with columns (resp. rows) filled with the same element given by sequence A134309 = (1, 1, 2, 4, 8, 16, ...), i. e., restricted to upper left 5 X 5 square:
( 1 ) ( 1 ) ( 1 )
( 1 1 ) ( 1 1 ) ( 1 1 )
(this) = ( 1 1 2 ) + ( 2 2 2 ) - ( 1 1 1 ) . (End)
( 1 1 2 4 ) ( 4 4 4 4 ) ( 1 1 1 1 )
( 1 1 2 4 8 ) ( 8 8 8 8 8 ) ( 1 1 1 1 1 )

Examples

			First few rows of the triangle:
   1;
   1,  1;
   2,  2,  3;
   4,  4,  5,  7;
   8,  8,  9, 11, 15;
  16, 16, 17, 19, 23, 31;
  32, 32, 33, 35, 39, 47, 63;
  ...
		

Crossrefs

Cf. A000012 (all 1's), A134309 = diag(A011782 = 2^max(n-1,0), n >= 0), A000079.
Row sums are A134311.

Programs

Formula

(A000012 * A134309 + A134309 * A000012) - A000012, as infinite lower triangular matrices, where A000012 = (1; 1,1; 1,1,1; ...), and A134309 = diag(1, 1, 2, 4, 8, 16, ...) = diag(A011782 = 1 followed by 1, 2, 4, 8, ... = powers of 2).
Row sums: A134311 = (1, 2, 7, 20, 51, 122, 281, 632, ...).

Extensions

Edited and offset corrected to 0 by M. F. Hasler, Mar 29 2022

A134464 (A127648 * A000012 + A000012 * A127773) - A000012.

Original entry on oeis.org

1, 2, 4, 3, 5, 8, 4, 6, 9, 13, 5, 7, 10, 14, 19, 6, 8, 11, 15, 20, 26, 7, 9, 12, 16, 21, 27, 34, 8, 10, 13, 17, 22, 28, 35, 43, 9, 11, 14, 18, 23, 29, 36, 44, 53, 10, 12, 15, 19, 24, 30, 37, 45, 54, 64
Offset: 1

Views

Author

Gary W. Adamson, Oct 26 2007

Keywords

Comments

Row sums = A134465: (1, 6, 16, 32, 55, 86, ...).

Examples

			First few rows of the triangle:
  1;
  2,  4;
  3,  5,  8;
  4,  6,  9, 13;
  5,  7, 10, 14, 19;
  6,  8, 11, 15, 20, 26;
  7,  9, 12, 16, 21, 27, 34;
  ...
		

Crossrefs

Programs

  • Mathematica
    Flatten[Table[RecurrenceTable[{a[1]==i,a[n]==a[n-1]+n},a,{n,i}],{i,10}]] (* Harvey P. Dale, Nov 12 2013 *)

Formula

(A127648 * A000012 * A000012 * A127773) - A000012, as infinite lower triangular matrices.

A134674 A134673 * A000012.

Original entry on oeis.org

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

Views

Author

Gary W. Adamson, Nov 05 2007

Keywords

Comments

Left column = A073757: (1, 2, 3, 4, 5, 5, 7, 8, 8, 7, ...).
Row sums = A134675: (1, 4, 9, 15, 25, 30, 49, 55, 80, ...).
n-th row (n>1) has n terms of "n", iff n is prime.

Examples

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

Crossrefs

Formula

A134673 * A000012 as infinite lower triangular matrices. Triangle, partial sums of A134673 starting from the right of each row.
A134674(n,k) = Sum_{j=n-k+1..n} A134673(n,j).

A134699 Triangle read by rows: A051731^2 * A000012.

Original entry on oeis.org

1, 3, 1, 3, 1, 1, 6, 3, 1, 1, 3, 1, 1, 1, 1, 9, 5, 3, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 10, 6, 3, 3, 1, 1, 1, 1, 6, 3, 3, 1, 1, 1, 1, 1, 1, 9, 5, 3, 3, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 18, 12, 8, 5, 3, 3, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 1

Views

Author

Gary W. Adamson, Nov 06 2007

Keywords

Comments

Left column = A007425.
Row sums = A007429: (1, 4, 5, 11, 7, 20, ...).

Examples

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

Crossrefs

Formula

A051731^2 * A000012 = A127170 * A000012, as infinite lower triangular matrices.

Extensions

More terms from Jinyuan Wang, Apr 29 2025

A135221 Triangle A007318 + A000012(signed) - I, I = Identity matrix, read by rows.

Original entry on oeis.org

1, 0, 1, 2, 1, 1, 0, 4, 2, 1, 2, 3, 7, 3, 1, 0, 6, 9, 11, 4, 1, 2, 5, 16, 19, 16, 5, 1, 0, 8, 20, 36, 34, 22, 6, 1, 2, 7, 29, 55, 71, 55, 29, 7, 1, 0, 10, 35, 85, 125, 127, 83, 37, 8, 1, 2, 9, 46, 119, 211, 251, 211, 119, 46, 9, 1, 0, 12, 54, 166, 329, 463, 461, 331, 164, 56, 10, 1
Offset: 0

Views

Author

Gary W. Adamson, Nov 23 2007

Keywords

Comments

row sums = A051049: (1, 1, 4, 7, 16, 31, 64, ...).

Examples

			First few rows of the triangle:
  1;
  0, 1;
  2, 1,  1;
  0, 4,  2,  1;
  2, 3,  7,  3,  1;
  0, 6,  9, 11,  4,  1;
  2, 5, 16, 19, 16,  5,  1;
  0, 8, 20, 36, 34, 22,  6, 1;
  2, 7, 29, 55, 71, 55, 29, 7, 1;
...
		

Crossrefs

Programs

  • GAP
    T:= function(n,k)
        if k=n then return 1;
        else return Binomial(n,k) + (-1)^(n-k);
        fi; end;
    Flat(List([0..12], n-> List([0..n], k-> T(n,k) ))); # G. C. Greubel, Nov 20 2019
  • Magma
    T:= func< n,k | k eq n select 1 else Binomial(n,k) +(-1)^(n-k) >;
    [T(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Nov 20 2019
    
  • Maple
    seq(seq( `if`(k=n, 1, binomial(n,k) + (-1)^(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, Binomial[n, k] + (-1)^(n-k)] ;
    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, binomial(n,k) + (-1)^(n-k)); \\ G. C. Greubel, Nov 20 2019
    
  • Sage
    def T(n, k):
        if (k==n): return 1
        else: return binomial(n,k) + (-1)^(n-k)
    [[T(n, k) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Nov 20 2019
    

Formula

T(n,k) = A007318 + A000012(signed) - Identity matrix, where A000012(signed) = (1; -1,1; 1,-1,1; ...).
T(n,k) = (-1)^(n-k) + binomial(n,k), with T(n,n)=1. - G. C. Greubel, Nov 20 2019

Extensions

More terms added by G. C. Greubel, Nov 20 2019

A135222 Triangle A049310 + A000012 - I, read by rows.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 2, 1, 4, 1, 1, 1, 4, 1, 5, 1, 1, 2, 1, 7, 1, 6, 1, 1, 1, 5, 1, 11, 1, 7, 1, 1, 2, 1, 11, 1, 16, 1, 8, 1, 1, 1, 6, 1, 21, 1, 22, 1, 9, 1, 1, 2, 1, 16, 1, 36, 1, 29, 1, 10, 1, 1, 1, 7, 1, 36, 1, 57, 1, 37, 1, 11, 1, 1, 2, 1, 22, 1, 71, 1, 85, 1, 46, 1, 12, 1, 1
Offset: 0

Views

Author

Gary W. Adamson, Nov 23 2007

Keywords

Comments

Row sums = A081659: (1, 2 4, 6, 9, 13, 19, 28, ...).

Examples

			First few rows of the triangle:
  1;
  1, 1;
  2, 1,  1;
  1, 3,  1,  1;
  2, 1,  4,  1,  1;
  1, 4,  1,  5,  1, 1;
  2, 1,  7,  1,  6, 1, 1;
  1, 5,  1, 11,  1, 7, 1, 1;
  2, 1, 11,  1, 16, 1, 8, 1, 1;
...
		

Crossrefs

Programs

  • Maple
    T:= proc(n, k) option remember;
          if k=n then 1
        else 1 + abs( ((1+(-1)^(n-k))/2)*binomial((n+k)/2, (n-k)/2)*cos((n-k)*Pi/2) )
          fi; end:
    seq(seq(T(n, k), k=0..n), n=0..15); # G. C. Greubel, Nov 20 2019
  • Mathematica
    T[n_, k_]:= T[n, k]= If[k==n, 1, 1 + Abs[Simplify[((1+(-1)^(n-k))/2)* Binomial[(n+k)/2, (n-k)/2]*Cos[(n-k)*Pi/2]]] ]; Table[T[n, k], {n,0,15}, {k,0,n}]//Flatten (* G. C. Greubel, Nov 20 2019 *)
  • Sage
    @CachedFunction
    def T(n, k):
        if (k==n): return 1
        else: return 1 + abs( ((1+(-1)^(n-k))/2)*binomial((n+k)/2, (n-k)/2)*cos((n-k)*pi/2) )
    [[T(n, k) for k in (0..n)] for n in (0..15)] # G. C. Greubel, Nov 20 2019

Formula

T(n,k) = A049310(n,k) + A000012(n,k) - Identity matrix, as infinite lower triangular matrices.
T(n,k) = 1 + abs( ((1+(-1)^(n-k))/2)*binomial((n+k)/2, (n-k)/2)*cos((n-k)*Pi/2) ), with T(n,n) = 1. - G. C. Greubel, Nov 20 2019

Extensions

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

A135223 Triangle A000012 * A127648 * A103451, read by rows.

Original entry on oeis.org

1, 3, 2, 6, 2, 3, 10, 2, 3, 4, 15, 2, 3, 4, 5, 21, 2, 3, 4, 5, 6, 28, 2, 3, 4, 5, 6, 7, 36, 2, 3, 4, 5, 6, 7, 8, 45, 2, 3, 4, 5, 6, 7, 8, 9, 55, 2, 3, 4, 5, 6, 7, 8, 9, 10, 66, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 78, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 91, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
Offset: 1

Views

Author

Gary W. Adamson, Nov 23 2007

Keywords

Comments

Row sums = A028387.

Examples

			First few rows of the triangle are:
   1;
   3, 2;
   6, 2, 3;
  10, 2, 3, 4;
  15, 2, 3, 4, 5;
...
		

Crossrefs

Programs

  • GAP
    T:= function(n,k)
        if k=1 then return Binomial(n+1,2);
        else return k;
        fi; end;
    Flat(List([1..15], n-> List([1..n], k-> T(n,k) ))); # G. C. Greubel, Nov 20 2019
  • Magma
    [k eq 1 select Binomial(n+1,2) else k: k in [1..n], n in [1..15]]; // G. C. Greubel, Nov 20 2019
    
  • Maple
    seq(seq( `if`(k=1, binomial(n+1,2), k), k=1..n), n=1..15); # G. C. Greubel, Nov 20 2019
  • Mathematica
    T[n_, k_]:= T[n, k]= If[k==1, Binomial[n+1, 2], k]; Table[T[n, k], {n, 15}, {k,n}]//Flatten (* G. C. Greubel, Nov 20 2019 *)
  • PARI
    T(n,k) = if(k==1, binomial(n+1,2), k); \\ G. C. Greubel, Nov 20 2019
    
  • Sage
    @CachedFunction
    def T(n,k):
        if (k==1): return binomial(n+1, 2)
        else: return k
    [[T(n,k) for k in (1..n)] for n in (1..15)] # G. C. Greubel, Nov 20 2019
    

Formula

T(n,k) = A000012(n,k) * A127648(n,k) * A103451(n,k) as infinite lower triangular matrices. Replace left border of 1's in A002260 with (1, 3, 6, 10, 15, ...).
T(n, k) = k with T(n,1) = binomial(n+1, 2). - G. C. Greubel, Nov 20 2019

Extensions

More terms added by G. C. Greubel, Nov 20 2019

A135224 Triangle A103451 * A007318 * A000012, read by rows. T(n, k) for 0 <= k <= n.

Original entry on oeis.org

1, 3, 1, 5, 3, 1, 9, 7, 4, 1, 17, 15, 11, 5, 1, 33, 31, 26, 16, 6, 1, 65, 63, 57, 42, 22, 7, 1, 129, 127, 120, 99, 64, 29, 8, 1, 257, 255, 247, 219, 163, 93, 37, 9, 1, 513, 511, 502, 466, 382, 256, 130, 46, 10, 1
Offset: 0

Views

Author

Gary W. Adamson, Nov 23 2007

Keywords

Comments

Row sums = A132750: (1, 4, 9, 21, 49, 113, ...).
Left border = A083318: (1, 3, 5, 9, 17, 33, ...).

Examples

			First few rows of the triangle:
   1;
   3,  1;
   5,  3,  1;
   9,  7,  4,  1;
  17, 15, 11,  5,  1;
  33, 31, 26, 16,  6,  1;
  65, 63, 57, 42, 22,  7,  1;
...
		

Crossrefs

Programs

  • Magma
    function T(n,k)
      if k eq 0 and n eq 0 then return 1;
      elif k eq 0 then return 2^n +1;
      else return (&+[Binomial(n, k+j): j in [0..n]]);
      end if; return T; end function;
    [T(n,k): k in [0..n], n in [0..10]]; // G. C. Greubel, Nov 20 2019
    
  • Maple
    T:= proc(n, k) option remember;
          if k=0 and n=0 then 1
        elif k=0 then 2^n +1
        else add(binomial(n, k+j), j=0..n)
          fi; end:
    seq(seq(T(n, k), k=0..n), n=0..10); # G. C. Greubel, Nov 20 2019
  • Mathematica
    T[n_, k_]:= T[n, k] = If[k==n==0, 1, If[k==0, 2^n +1, Sum[Binomial[n, k + j], {j, 0, n}]]]; Table[T[n, k], {n, 0, 10}, {k, 0, n}]//Flatten (* G. C. Greubel, Nov 20 2019 *)
  • PARI
    T(n,k) = if(k==0 && n==0, 1, if(k==0, 2^n +1, sum(j=0, n, binomial(n, k+j)) )); \\ G. C. Greubel, Nov 20 2019
    
  • Sage
    def T(n, k):
        if (k==0 and n==0): return 1
        elif (k==0): return 2^n + 1
        else: return sum(binomial(n, k+j) for j in (0..n))
    [[T(n, k) for k in (0..n)] for n in (0..10)] # G. C. Greubel, Nov 20 2019

Formula

T(n, k) = A103451(n,k) * A007318(n,k) * A000012(n,k) as infinite lower triangular matrices.
T(n, k) = Sum_{j=0..n} binomial(n, k+j), with T(0,0) = 1 and T(n,0) = 2^n + 1. - G. C. Greubel, Nov 20 2019
T(n, k) = binomial(n, k)*hypergeom([1, k-n], [k+1], -1) - binomial(n, k+n+1)* hypergeom([1, k+1], [k+n+2], -1) + 0^k - 0^n. - Peter Luschny, Nov 20 2019

A135227 Triangle A000012 * A135225, read by rows.

Original entry on oeis.org

1, 2, 1, 3, 2, 1, 4, 3, 3, 1, 5, 4, 6, 4, 1, 6, 5, 10, 10, 5, 1, 7, 6, 15, 20, 15, 6, 1, 8, 7, 21, 35, 35, 21, 7, 1, 9, 8, 28, 56, 70, 56, 28, 8, 1, 10, 9, 36, 84, 126, 126, 84, 36, 9, 1, 11, 10, 45, 120, 210, 252, 210, 120, 45, 10, 1, 12, 11, 55, 165, 330, 462, 462, 330, 165, 55, 11, 1
Offset: 0

Views

Author

Gary W. Adamson, Nov 23 2007

Keywords

Comments

Row sums = A006127: (1, 3, 6, 11, 20, 37, ...).

Examples

			First few rows of the triangle:
  1;
  2, 1;
  3, 2,  1;
  4, 3,  3,  1;
  5, 4,  6,  4,  1;
  6, 5, 10, 10,  5, 1;
  7, 6, 15, 20, 15, 6, 1;
...
		

Crossrefs

Programs

  • GAP
    T:= function(n,k)
        if k=0 then return 1;
        else return Binomial(n,k);
        fi; end;
    Flat(List([0..12], n-> List([0..n], k-> T(n,k) ))); # G. C. Greubel, Nov 20 2019
  • Magma
    [k eq 0 select n+1 else Binomial(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Nov 20 2019
    
  • Maple
    seq(seq( `if`(k=0, n+1, binomial(n,k)), k=0..n), n=0..12); # G. C. Greubel, Nov 20 2019
  • Mathematica
    Table[If[k==0, n+1, Binomial[n, k]], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Nov 20 2019 *)
  • PARI
    T(n,k) = if(k==0, n+1, binomial(n,k)); \\ G. C. Greubel, Nov 20 2019
    
  • Sage
    def T(n, k):
        if (k==0): return 1
        else: return binomial(n, k)
    [[T(n, k) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Nov 20 2019
    

Formula

A000012 * A135225 as infinite lower triangular matrices. Left border of 1's in Pascal's Triangle (A007318) is replaced with a column of (1,2,3,...).
T(n,k) = binomial(n,k), with T(n,0) = n+1. - G. C. Greubel, Nov 20 2019

Extensions

More terms added by G. C. Greubel, Nov 20 2019
Previous Showing 61-70 of 2634 results. Next