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 11-20 of 2635 results. Next

A131333 A131332 * A000012.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 3, 2, 2, 1, 5, 3, 4, 2, 1, 8, 5, 7, 4, 3, 1, 13, 8, 12, 7, 7, 3, 1, 21, 13, 20, 12, 14, 7, 4, 1, 34, 21, 33, 20, 26, 14, 11, 4, 1, 55, 34, 54, 33, 46, 26, 25, 11, 5, 1
Offset: 1

Views

Author

Gary W. Adamson, Jun 29 2007

Keywords

Comments

Leftmost two columns = Fibonacci numbers. Row sums = A029907: (1, 2, 4, 8, 15, 28, 51,...).

Examples

			First few rows of the triangle are:
1;
1, 1;
2, 1, 1;
3, 2, 2, 1;
5, 3, 4, 2, 1;
8, 5, 7, 4, 3, 1;
13, 8, 12, 7, 7, 3, 1;
21, 13, 20, 12, 14, 7, 4, 1;
...
		

Crossrefs

Formula

A131332 * A000012, where A000012 = (1; 1,1; 1,1,1;...). Partial sums of A131332 rows starting from the right.

A131334 A000012(signed) * A065941.

Original entry on oeis.org

1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 2, 1, 1, 0, 1, 2, 2, 2, 1, 1, 0, 3, 2, 4, 2, 1, 0, 1, 3, 3, 6, 4, 3, 1, 1, 0, 4, 3, 9, 6, 7, 3, 1, 0, 1, 4, 4, 12, 9, 13, 7, 4, 1
Offset: 1

Views

Author

Gary W. Adamson, Jun 29 2007

Keywords

Comments

Row sums = Fibonacci numbers.

Examples

			First few rows of the triangle are:
1;
0, 1;
1, 0, 1;
0, 1, 1, 1;
1, 0, 2, 1, 1;
0, 1, 2, 2, 2, 1;
1, 0, 3, 2, 4, 2, 1;
0, 1, 3, 3, 6, 4, 3, 1;
1, 0, 4, 3, 9, 6, 7, 3, 1;
...
		

Crossrefs

Formula

A000012(signed by columns, + - + -...) * A065941.

A131335 A000012 * A131334.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 2, 2, 2, 1, 3, 2, 4, 2, 1, 3, 3, 6, 4, 3, 1, 4, 3, 9, 6, 7, 3, 1, 4, 4, 12, 9, 13, 7, 4, 1, 5, 4, 16, 12, 22, 13, 11, 4, 1, 5, 5, 20, 16, 34, 22, 24, 11, 5, 1
Offset: 1

Views

Author

Gary W. Adamson, Jun 29 2007

Keywords

Comments

Row sums = A000071, Fibonacci numbers - 1, starting (1, 2, 4, 7, 12, 20, 33,...).

Examples

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

Crossrefs

Formula

A000012 * A131334 as infinite lower triangular matrices, where A000012 = (1; 1,1; 1,1,1;...).

A132823 A007318 + 2*A103451 - 2*A000012.

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 2, 4, 2, 1, 1, 3, 8, 8, 3, 1, 1, 4, 13, 18, 13, 4, 1, 1, 5, 19, 33, 33, 19, 5, 1, 1, 6, 26, 54, 68, 54, 26, 6, 1, 1, 7, 34, 82, 124, 124, 82, 34, 7, 1, 1, 8, 43, 118, 208, 250, 208, 118, 43, 8, 1, 1, 9, 53, 163, 328, 460, 460, 328, 163, 53, 9, 1
Offset: 0

Views

Author

Gary W. Adamson, Sep 02 2007

Keywords

Comments

Row sums = A132824: (1, 2, 2, 4, 10, 24, 54, 116, 242, ...).

Examples

			First few rows of the triangle:
  1;
  1, 1;
  1, 0,  1;
  1, 1,  1,  1;
  1, 2,  4,  2,   1;
  1, 3,  8,  8,   3,   1;
  1, 4, 13, 18,  13,   4,  1;
  1, 5, 19, 33,  33,  19,  5,  1;
  1, 6, 26, 54,  68,  54, 26,  6, 1;
  1, 7, 34, 82, 124, 124, 82, 34, 7, 1;
  ...
		

Crossrefs

A(2n,n) gives A115112 for n>0.

Formula

A007318 + 2*A103451 - 2*A000012 as infinite lower triangular matrices.

Extensions

One missing 1 inserted and more terms added by Alois P. Heinz, Feb 10 2019

A058393 A square array based on 1^n (A000012) with each term being the sum of 2 consecutive terms in the previous row.

Original entry on oeis.org

1, 0, 1, 1, 1, 1, 0, 1, 2, 1, 1, 1, 2, 3, 1, 0, 1, 2, 4, 4, 1, 1, 1, 2, 4, 7, 5, 1, 0, 1, 2, 4, 8, 11, 6, 1, 1, 1, 2, 4, 8, 15, 16, 7, 1, 0, 1, 2, 4, 8, 16, 26, 22, 8, 1, 1, 1, 2, 4, 8, 16, 31, 42, 29, 9, 1, 0, 1, 2, 4, 8, 16, 32, 57, 64, 37, 10, 1, 1, 1, 2, 4, 8, 16, 32, 63, 99, 93, 46, 11, 1, 0
Offset: 0

Views

Author

Henry Bottomley, Nov 24 2000

Keywords

Comments

Changing the formula by replacing T(0,2n)=T(1,n) by T(0,2n)=T(m,n) for some other value of m, would make the generating function change to coefficient of x^n in expansion of (1+x)^k/(1-x^2)^m. This would produce A058394, A058395, A057884, (and effectively A007318).

Examples

			Rows are (1,0,1,0,1,0,1,...), (1,1,1,1,1,1,...), (1,2,2,2,2,2,...), (1,3,4,4,4,...) etc.
		

Crossrefs

Rows are A000035 (A000012 with zeros), A000012, A040000 etc. Columns are A000012, A001477, A000124, A000125, A000127, A006261, A008859, A008860, A008861, A008862, A008863 etc. Diagonals include A000079, A000225, A000295, A002662, A002663, A002664, A035038, A035039, A035040, A035041, etc. The triangles A008949, A054143 and A055248 also appear in the half of the array which is not powers of 2.

Formula

T(n, k)=T(n-1, k-1)+T(n, k-1) with T(0, k)=1, T(1, 1)=1, T(0, 2n)=T(1, n) and T(0, 2n+1)=0. Coefficient of x^n in expansion of (1+x)^k/(1-x^2).

A130303 A130296 * A000012.

Original entry on oeis.org

1, 3, 1, 5, 2, 1, 7, 3, 2, 1, 9, 4, 3, 2, 1, 11, 5, 4, 3, 2, 1, 13, 6, 5, 4, 3, 2, 1, 15, 7, 6, 5, 4, 3, 2, 1, 17, 8, 7, 6, 5, 4, 3, 2, 1, 19, 9, 8, 7, 6, 5, 4, 3, 2, 1
Offset: 1

Views

Author

Gary W. Adamson, May 20 2007

Keywords

Examples

			1;
3, 1;
5, 2, 1;
7, 3, 2, 1;
9, 4, 3, 2, 1;
11, 5, 4, 3, 2, 1;
13, 6, 5, 4, 3, 2, 1;
15, 7, 6, 5, 4, 3, 2, 1;
17, 8, 7, 6, 5, 4, 3, 2, 1;
19, 9, 8, 7, 6, 5, 4, 3, 2, 1;
		

References

  • H. S. M. Coxeter, Regular Polytopes, 3rd ed., Dover, NY, 1973, pp 159-162

Crossrefs

Cf. A130296, A000012, A034856 (row sums), A130302 (commuted matrix product)

Programs

  • Mathematica
    Clear[e, n, k];
    e[n_, 0] := 2*n - 1;
    e[n_, k_] := 0 /; k >= n;
    e[n_, k_] := (e[n - 1, k]*e[n, k - 1] + 1)/e[n - 1, k - 1];
    Table[Table[e[n, k], {k, 0, n - 1}], {n, 1, 10}];
    Flatten[%]

Formula

A130296 * A000012 as infinite lower triangular matrices. (1,3,5,...) as the left border; (1,2,3,...) in all other columns.
e(n,k)= (e(n - 1, k)*e(n, k - 1) + 1)/e(n - 1, k - 1)

Extensions

Additional comments from Roger L. Bagula and Gary W. Adamson, Mar 28 2009

A131336 A131334 * A000012.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 3, 3, 2, 1, 5, 4, 4, 2, 1, 8, 8, 7, 5, 3, 1, 13, 12, 12, 9, 7, 3, 1, 21, 21, 20, 17, 14, 8, 4, 1, 34, 33, 33, 29, 26, 17, 11, 4, 1, 55, 55, 54, 50, 46, 34, 25, 12, 5, 1
Offset: 1

Views

Author

Gary W. Adamson, Jun 29 2007

Keywords

Comments

Left border = Fibonacci numbers. Row sums = A131337.

Examples

			First few rows of the triangle are:
1;
1, 1;
2, 1, 1;
3, 3, 2, 1;
5, 4, 4, 2, 1;
8, 8, 7, 5, 3, 1;
13, 12, 12, 9, 7, 3, 1;
21, 21, 20 17, 14, 8, 4, 1;
...
		

Crossrefs

Formula

A131334 * A000012, (partial row sums of A131334 starting from the right).

A131410 A127647 * A000012.

Original entry on oeis.org

1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 5, 5, 5, 5, 5, 8, 8, 8, 8, 8, 8, 13, 13, 13, 13, 13, 13, 13, 21, 21, 21, 21, 21, 21, 21, 21, 34, 34, 34, 34, 34, 34, 34, 34, 34, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 144, 144, 144
Offset: 1

Views

Author

Gary W. Adamson, Jul 08 2007

Keywords

Comments

Row sums = A045925, n*Fib(n): (1, 2, 6, 12, 25, 48,...).

Examples

			First few rows of the triangle are:
1;
1, 1;
2, 2, 2;
3, 3, 3, 3;
5, 5, 5, 5, 5;
8, 8, 8, 8, 8, 8;
...
		

Crossrefs

Programs

  • Haskell
    a131410 n k = a131410_tabl !! (n-1) !! (n-1)
    a131410_row n = a131410_tabl !! (n-1)
    a131410_tabl = zipWith replicate [1..] $ tail a000045_list
    -- Reinhard Zumkeller, Oct 07 2012
  • Mathematica
    Table[Fibonacci[n], {n, 15}, {n}] // Flatten (* Vincenzo Librandi, Jan 28 2017 *)

Formula

A127647 * A000012 as infinite lower triangular matrices.
Partial sums of A127647 starting from the right, read by rows.
By rows, F(n) occurs n times.

A131437 (A000012 * A131436) + (A131436 * A000012) - A000012.

Original entry on oeis.org

1, 3, 5, 7, 9, 13, 15, 17, 21, 29, 31, 33, 37, 45, 61, 63, 65, 69, 77, 93, 125, 127, 129, 133, 141, 157, 189, 253, 255, 257, 261, 269, 285, 317, 381, 509, 511, 513, 517, 525, 541, 573, 637, 765, 1021, 1023, 1025, 1029, 1037, 1053, 1085, 1149, 1277, 1533, 2045
Offset: 1

Views

Author

Gary W. Adamson, Jul 11 2007

Keywords

Comments

Left column = 2^n - 1; right border = A036563, 2^(n+1) - 3: (1, 5, 13, 29, 61, 125, ...). Row sums = A131438: (1, 8, 29, 82, 207, 492, 1129, ...).

Examples

			First few rows of the triangle are:
1;
3, 5;
7, 9, 13;
15, 17, 21, 29;
31, 33, 37, 45, 61;
63, 65, 69, 77, 93, 125;
...
		

Crossrefs

Programs

Formula

(A000012 * A131436) + (A131436 * A000012) - A000012; as infinite lower triangular matrices.

Extensions

Corrected by R. J. Mathar, Sep 24 2011

A131843 Triangle read by rows: 2*A131821 - A000012.

Original entry on oeis.org

1, 3, 3, 5, 1, 5, 7, 1, 1, 7, 9, 1, 1, 1, 9, 11, 1, 1, 1, 1, 11, 13, 1, 1, 1, 1, 1, 13, 15, 1, 1, 1, 1, 1, 1, 15, 17, 1, 1, 1, 1, 1, 1, 1, 17, 19, 1, 1, 1, 1, 1, 1, 1, 1, 19, 21, 1, 1, 1, 1, 1, 1, 1, 1, 1, 21, 23, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 23, 25, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 25, 27, 1, 1, 1, 1, 1
Offset: 0

Views

Author

Gary W. Adamson, Jul 21 2007

Keywords

Comments

Row sums = 5*n + 1, A016861: (1, 6, 11, 16, 21, ...).

Examples

			First few rows of the triangle are:
   1;
   3,  3;
   5,  1,  5;
   7,  1,  1,  7;
   9,  1,  1,  1,  9;
  11,  1,  1,  1,  1, 11;
  ...
		

Crossrefs

Formula

2*A131821 - A000012 as an infinite lower triangular matrix. 2*n - 1, (1, 3, 5, 7, ...) as right and left borders, with the rest zeros.

Extensions

Corrected and edited by B. D. Swan (bdswan(AT)gmail.com), Dec 20 2008
Previous Showing 11-20 of 2635 results. Next