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 11-13 of 13 results.

A350492 Number of unlabeled acyclic digraphs with n arcs and a global source and sink.

Original entry on oeis.org

1, 1, 1, 2, 5, 14, 44, 153, 584, 2414, 10732, 50909, 256198, 1360645, 7593530, 44366458, 270517289, 1716555943, 11308051214, 77170484915, 544525867544, 3965944595335, 29769162604337, 229970873746105, 1826057472681595, 14886348784740516
Offset: 0

Views

Author

Andrew Howroyd, Jan 08 2022

Keywords

Crossrefs

Column sums of A350491.

Programs

A350490 Number of unlabeled acyclic digraphs with n arcs and a global source.

Original entry on oeis.org

1, 1, 2, 5, 15, 50, 191, 795, 3625, 17781, 93319, 519732, 3056185, 18880345, 122066437, 823118881, 5772473719, 41995743085, 316258151517, 2460542117337, 19743544526463, 163138014893817, 1386173917051704, 12096681529032989, 108293699332498981
Offset: 0

Views

Author

Andrew Howroyd, Jan 08 2022

Keywords

Crossrefs

Column sums of A350488.

Programs

A350448 Triangle read by rows: T(n,k) is the number of acyclic graphs on n unlabeled nodes whose longest directed path has k arcs.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 3, 2, 0, 1, 8, 14, 8, 0, 1, 20, 89, 128, 64, 0, 1, 55, 634, 1934, 2336, 1024, 0, 1, 163, 5668, 36428, 83648, 84992, 32768, 0, 1, 556, 67926, 959718, 3919584, 7097088, 6144000, 2097152, 0, 1, 2222, 1137641, 37205922, 268989920, 793138688, 1175224320, 880803840, 268435456, 0
Offset: 0

Views

Author

Andrew Howroyd, Dec 31 2021

Keywords

Examples

			Triangle begins:
  1;
  1,   0;
  1,   1,    0;
  1,   3,    2,     0;
  1,   8,   14,     8,     0;
  1,  20,   89,   128,    64,     0;
  1,  55,  634,  1934,  2336,  1024,     0;
  1, 163, 5668, 36428, 83648, 84992, 32768, 0;
  ...
		

Crossrefs

Row sums are A003087.
Diagonals include A000007, A006125.
Cf. A122078.

Programs

  • PARI
    \\ See PARI link in A122078 for program code.
    { my(T=AcyclicDigraphsByLongestPath(8)); for(n=1, #T, print(T[n])) }
Previous Showing 11-13 of 13 results.