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 1-4 of 4 results.

A366567 a(n) is the mode of the probability distributions from which the expected game lengths in A366566 were determined.

Original entry on oeis.org

2, 3, 4, 7, 10, 11, 16, 19, 22, 27, 32, 37, 42, 47, 54, 59
Offset: 1

Views

Author

Hugo Pfoertner, Oct 13 2023

Keywords

Comments

See A366566 for more information.

Crossrefs

A366166 Decimal expansion of sqrt(Pi)/(3*sqrt(3))*(Gamma(1/3)/Gamma(5/6))^3.

Original entry on oeis.org

4, 5, 5, 9, 7, 9, 4, 4, 9, 9, 9, 5, 9, 8, 4, 5, 8, 1, 5, 4, 8, 1, 7, 3, 6, 4, 8, 4, 5, 5, 7, 2, 4, 8, 1, 1, 7, 6, 3, 6, 7, 4, 2, 3, 8, 0, 1, 6, 6, 1, 4, 0, 5, 6, 3, 5, 0, 5, 1, 8, 3, 8, 7, 6, 5, 4, 7, 2, 1, 1, 5, 9, 5, 9, 3, 5, 5, 7, 0, 4, 4, 9, 2, 3, 2, 4, 8, 7, 9, 6
Offset: 1

Views

Author

Hugo Pfoertner, Oct 13 2023

Keywords

Comments

This constant c occurs in the probability that the "big player" in a game with 3 gamblers goes broke first, although he starts with an initial capital of N-2 units, whereas the other two gamblers start with one unit each. This probability is ~ c/N^3. See Diaconis link for details.

Examples

			4.5597944999598458154817364845572481176367423801661405635...
		

Crossrefs

Programs

  • Mathematica
    First[RealDigits[Gamma[1/3]^9/(2Pi)^4,10,100]] (* Paolo Xausa, Oct 14 2023 *)
  • PARI
    sqrt(Pi)/(3*sqrt(3))*(gamma(1/3)/gamma(5/6))^3

Formula

Equals Gamma(1/3)^9 / (2*Pi)^4. - Peter Luschny, Oct 13 2023

A366995 a(n) is the numerator of the expected end time of a game with three gamblers, one of which starts with capital n, the others with capital 1 each, conditional on the event that one of the two poor players wins.

Original entry on oeis.org

3, 39, 359, 2477, 119667, 1522705, 46419629, 6143100517, 5472109127035, 790136773603303, 278129286200597661, 16684426086791338103, 503067648850136040148699, 2626565018569118643191009, 10920130209346850287269887104735, 236686188450953790757840351941895
Offset: 1

Views

Author

Pontus von Brömssen, Oct 31 2023

Keywords

Comments

In each round of the game, 1 unit is transferred from one randomly chosen player to another. Players play until they are out of money, so when the first player is out the other two continue to play. The winner is the player who ends up with all n+2 units of money.

Crossrefs

Cf. A366566 (a(n)/A366996(n) rounded to nearest integer), A366996 (denominators).

Programs

  • Sage
    from itertools import permutations
    def T(n):
        nodes = [(i,j) for i in range(n+2) for j in range((n+2-i)//2+1)]
        m = len(nodes)
        Q0 = {x:{y:0 for y in nodes} for x in nodes}
        for x in nodes:
            c1 = x+(n+2-sum(x),)
            for i,j in permutations(range(3),int(2)):
                if c1[i] and c1[j]:
                    c2 = list(c1)
                    c2[i] -= 1
                    c2[j] += 1
                    y = (c2[0],min(c2[1:]))
                    if c2[0] != n+2:
                        Q0[x][y] += n+2-c2[0]
        Q0 = matrix(QQ,[list(R.values()) for R in Q0.values()])
        s = sum(Q0.columns())
        Q = identity_matrix(QQ,m-1)
        for i in range(1,m):
            for j in range(1,m):
                if s[i] != 0: Q[i-1,j-1] -= Q0[i,j]/s[i]
        return (Q**(-1)*ones_matrix(QQ,m-1))[-2,0]
    def A366995(n):
        return T(n).numerator()
    def A366996(n):
        return T(n).denominator()

A366996 a(n) is the denominator of the expected end time of a game with three gamblers, one of which starts with capital n, the others with capital 1 each, conditional on the event that one of the two poor players wins.

Original entry on oeis.org

1, 7, 41, 197, 7025, 68761, 1663251, 178945525, 132150155017, 16077043550231, 4833128874789907, 250487901809049775, 6590569678028479808009, 30288529373611329886681, 111694000110134843095617996833, 2161868815213291879136716036071, 7842015457241561891262053489240216057
Offset: 1

Views

Author

Pontus von Brömssen, Oct 31 2023

Keywords

Comments

In each round of the game, 1 unit is transferred from one randomly chosen player to another. Players play until they are out of money, so when the first player is out the other two continue to play. The winner is the player who ends up with all n+2 units of money.
See A366995 for references and programs.

Crossrefs

Cf. A366566 (A366995(n)/a(n) rounded to nearest integer), A366995 (numerators).
Showing 1-4 of 4 results.