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 1-5 of 5 results.

A367995 a(n) is the denominator of the probability that the free polyomino with binary code A246521(n+1) appears as the image of a simple random walk on the square lattice.

Original entry on oeis.org

1, 1, 3, 3, 21, 21, 7, 21, 21, 1001, 77, 77, 77, 1001, 77, 77, 1001, 1001, 77, 91, 77, 89089, 785603, 143, 143, 24297, 143, 25924899, 97097, 785603, 97097, 25924899, 143, 89089, 143, 97097, 97097, 143, 25924899, 97097, 97097, 143, 143, 97097, 143, 97097, 143, 143, 97097, 97097, 97097, 143, 97097, 291291, 291291, 143
Offset: 1

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Author

Pontus von Brömssen, Dec 08 2023

Keywords

Comments

In a simple random walk on the square lattice, draw a unit square around each visited point. A367994(n)/a(n) is the probability that, when the appropriate number of distinct points have been visited, the drawn squares form the free polyomino with binary code A246521(n+1).
Can be read as an irregular triangle, whose n-th row contains A000105(n) terms, n >= 1.

Examples

			As an irregular triangle:
     1;
     1;
     3,  3;
    21, 21,  7, 21,   21;
  1001, 77, 77, 77, 1001, 77, 77, 1001, 1001, 77, 91, 77;
  ...
There are only one monomino and one free domino, so both of these appear with probability 1, and a(1) = a(2) = 1.
For three squares, the probability for an L (or right) tromino (whose binary code is 7 = A246521(4)) is 2/3, so a(3) = 3. The probability for the straight tromino (whose binary code is 11 = A246521(5)) is 1/3, so a(4) = 3.
		

Crossrefs

Formula

A367994(n)/a(n) = (A368000(n)/A368001(n))*A335573(n+1).

A367998 Numerator of the greatest probability that a particular free polyomino with n cells appears as the image of a simple random walk on the square lattice.

Original entry on oeis.org

1, 1, 2, 8, 388, 2495, 13652575732976, 1580140554389506598141638, 2303282945504494379369753334706333784257298061180917309, 1116351824215919296474220471583292515147278170740521646743561595082143234790184233409933250330039986837258312677349601942095851
Offset: 1

Views

Author

Pontus von Brömssen, Dec 08 2023

Keywords

Comments

a(n) is the numerator of the maximum of A367994/A367995 over the n-th row. See A367994 for details.

Examples

			For 1 <= n <= 13, the following are all polyominoes that have the maximum probabilities for their respective sizes. Except for n = 7, there is just one such polyomino.
                    _      _      _ _
        _    _     | |    | |_   |   |
   _   | |  | |_   | |_   |   |  |   |
  |_|  |_|  |_ _|  |_ _|  |_ _|  |_ _|
            _                 _ _
   _ _     | |_    _ _      _|   |
  |   |    |   |  |   |_   |    _|
  |   |_   |   |  |     |  |   |
  |_ _ _|  |_ _|  |_ _ _|  |_ _|
   _ _      _ _        _ _        _ _ _
  |   |    |   |_    _|   |_    _|     |
  |   |_   |     |  |       |  |      _|
  |     |  |     |  |    _ _|  |     |
  |_ _ _|  |_ _ _|  |_ _|      |_ _ _|
		

Crossrefs

A368005 Denominator of the greatest probability that a particular fixed polyomino with n cells appears as the image of a simple random walk on the square lattice.

Original entry on oeis.org

1, 2, 6, 21, 2002, 48594, 6786340869, 60683548875931642773982870, 148748699073930002409397035, 98235230940726955523493708384725766221632599616516980478369143134298250712431827891413914221729825
Offset: 1

Views

Author

Pontus von Brömssen, Dec 21 2023

Keywords

Comments

a(n) is the denominator of the maximum of A368000/A368001 over the n-th row. See A368000 for details.

Examples

			See A368004.
		

Crossrefs

A367997 Denominator of the least probability that a particular free polyomino with n cells appears as the image of a simple random walk on the square lattice.

Original entry on oeis.org

1, 1, 3, 21, 91, 291291, 17574557, 1433685253, 2819787, 14870951705, 124958680680282, 3525784478869018946300814, 27359333221
Offset: 1

Views

Author

Pontus von Brömssen, Dec 08 2023

Keywords

Comments

a(n) is the denominator of the minimum of A367994/A367995 over the n-th row. See A367994 for details.

Crossrefs

Cf. A367994, A367995, A367996 (numerators), A367999, A368003.

A368391 Denominator of the greatest probability that a particular free polyomino with n cells appears in internal diffusion-limited aggregation on the square lattice.

Original entry on oeis.org

1, 1, 3, 35, 154, 492573081, 2263639868336, 2851008421256134796827810712799257125795200, 23733667150026775615685852367392733768076432660227006271200, 153969151852607771689295889934692329991676103836044675654575411018653133479482476448000
Offset: 1

Views

Author

Pontus von Brömssen, Dec 22 2023

Keywords

Comments

a(n) is the denominator of the maximum of A368386/A368387 over the n-th row. See A368386 for details.

Examples

			See A368390.
		

Crossrefs

Cf. A367674, A367763, A367999, A368386, A368387, A368389, A368390 (numerators), A368395, A368662 (external diffusion-limited aggregation).
Showing 1-5 of 5 results.