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.

Showing 1-7 of 7 results.

A351357 Irregular triangle read by rows T(n,k): number of binary necklaces with n beads, k of them black, and at least three consecutive black beads.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 2, 1, 1, 0, 0, 0, 1, 3, 3, 1, 1, 0, 0, 0, 1, 4, 6, 4, 1, 1, 0, 0, 0, 1, 5, 10, 9, 4, 1, 1, 0, 0, 0, 1, 6, 15, 19, 12, 5, 1, 1, 0, 0, 0, 1, 7, 21, 33, 29, 15, 5, 1, 1, 0, 0, 0, 1, 8, 28, 54, 60, 42, 19, 6, 1, 1, 0, 0, 0, 1, 9, 36, 81, 111, 96, 55, 22, 6, 1, 1
Offset: 1

Views

Author

Marko Riedel, Feb 08 2022

Keywords

Examples

			Triangle begins:
  0, 0;
  0, 0, 0;
  0, 0, 0, 1;
  0, 0, 0, 1, 1;
  0, 0, 0, 1, 1, 1;
  0, 0, 0, 1, 2, 1, 1;
  0, 0, 0, 1, 3, 3, 1, 1;
  0, 0, 0, 1, 4, 6, 4, 1, 1;
		

Crossrefs

Row sums are A351360.

A351358 Irregular triangle read by rows T(n,k): number of binary necklaces with n beads, k of them black, and at least four consecutive black beads.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 2, 1, 1, 0, 0, 0, 0, 1, 3, 3, 1, 1, 0, 0, 0, 0, 1, 4, 6, 4, 1, 1, 0, 0, 0, 0, 1, 5, 10, 10, 5, 1, 1, 0, 0, 0, 0, 1, 6, 15, 20, 14, 5, 1, 1, 0, 0, 0, 0, 1, 7, 21, 35, 34, 18, 6, 1, 1, 0, 0, 0, 0, 1, 8, 28, 56, 68, 50, 22, 6, 1, 1
Offset: 1

Views

Author

Marko Riedel, Feb 08 2022

Keywords

Examples

			Triangle begins:
  0, 0;
  0, 0, 0;
  0, 0, 0, 0;
  0, 0, 0, 0, 1;
  0, 0, 0, 0, 1, 1;
  0, 0, 0, 0, 1, 1, 1;
  0, 0, 0, 0, 1, 2, 1, 1;
  0, 0, 0, 0, 1, 3, 3, 1, 1;
		

Crossrefs

Formula

Row sums are A351361.

A351360 Number of binary necklaces with n beads and at least three consecutive black beads.

Original entry on oeis.org

0, 0, 1, 2, 3, 5, 9, 17, 31, 60, 113, 220, 419, 813, 1565, 3033, 5855, 11358, 21977, 42644, 82675, 160517, 311609, 605551, 1176871, 2288964, 4453237, 8669002, 16881859, 32892459, 64112225, 125022545, 243898335, 476011102, 929387453, 1815322932
Offset: 1

Views

Author

Marko Riedel, Feb 08 2022

Keywords

Crossrefs

Formula

a(n) = A000031(n) - A093305(n).

A351361 Number of binary necklaces with n beads and at least four consecutive black beads.

Original entry on oeis.org

0, 0, 0, 1, 2, 3, 5, 9, 17, 33, 63, 124, 241, 475, 930, 1831, 3593, 7077, 13905, 27377, 53847, 106006, 208601, 410723, 808514, 1592123, 3135085, 6174695, 12161761, 23957945, 47198847, 92997768, 183253045, 361145269, 711793554, 1403055509, 2765913617
Offset: 1

Views

Author

Marko Riedel, Feb 08 2022

Keywords

Crossrefs

Formula

a(n) = A000031(n) - A280218(n).

A351356 Triangle read by rows T(n,k): number of binary necklaces with n beads, k of them black, and at least two consecutive black beads.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 2, 1, 1, 0, 0, 1, 3, 3, 1, 1, 0, 0, 1, 4, 5, 3, 1, 1, 0, 0, 1, 5, 9, 7, 4, 1, 1, 0, 0, 1, 6, 13, 14, 10, 4, 1, 1, 0, 0, 1, 7, 19, 25, 22, 12, 5, 1, 1, 0, 0, 1, 8, 25, 41, 42, 30, 15, 5, 1, 1, 0, 0, 1, 9, 33, 63, 79, 66, 43, 19, 6, 1, 1, 0, 0, 1, 10, 41, 92, 131, 132, 99, 55, 22, 6, 1, 1
Offset: 1

Views

Author

Marko Riedel, Feb 08 2022

Keywords

Examples

			Triangle begins:
  0;
  0, 0;
  0, 1, 0;
  0, 1, 1, 0;
  0, 1, 1, 1, 0;
  0, 1, 2, 1, 1, 0;
  0, 1, 3, 3, 1, 1, 0;
  0, 1, 4, 5, 3, 1, 1, 0;
  0, 1, 5, 9, 7, 4, 1, 1, 0;
  ...
		

Crossrefs

Row sums are A351359.

A351363 Number of necklaces with n black and n white beads with at least four consecutive black beads.

Original entry on oeis.org

0, 0, 0, 1, 5, 21, 84, 327, 1251, 4760, 18018, 68104, 257088, 970480, 3664070, 13842215, 52331695, 198021936, 750027090, 2843686271, 10792866315, 41006110365, 155961264880, 593797895358, 2263126224780, 8634161689920, 32973466762098, 126047166461574, 482298648250416, 1847156083546316
Offset: 1

Views

Author

Marko Riedel, Feb 08 2022

Keywords

Crossrefs

Formula

a(n) = A003239(n) - A351364(n).

A351364 Number of necklaces with n black and n white beads that avoid the pattern BBBB.

Original entry on oeis.org

1, 2, 4, 9, 21, 59, 162, 483, 1453, 4492, 14048, 44616, 142936, 462380, 1506534, 4941955, 16303783, 54066560, 180111432, 602481589, 2022797529, 6814336663, 23026359634, 78027238290, 265085903996, 902733374480, 3080967048004, 10536594982790, 36102498293396, 123920278459564
Offset: 1

Views

Author

Marko Riedel, Feb 08 2022

Keywords

Crossrefs

Formula

a(n) = A003239(n) - A351363(n).
Showing 1-7 of 7 results.