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 1-2 of 2 results.

A030699 Maximal value of Q(n,m) (number of partitions of n into m distinct summands) for given n.

Original entry on oeis.org

1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 7, 8, 10, 12, 14, 16, 19, 21, 24, 27, 34, 39, 47, 54, 64, 72, 84, 94, 108, 120, 136, 150, 169, 192, 221, 255, 291, 333, 377, 427, 480, 540, 603, 674, 748, 831, 918, 1014, 1115, 1226, 1360, 1540, 1729, 1945, 2172, 2432, 2702, 3009
Offset: 1

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Author

Keywords

References

  • L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 115.

Crossrefs

Programs

  • Mathematica
    Max /@ Table[Length@ Select[IntegerPartitions[n, m], Sort@ DeleteDuplicates@ # == Range@ m &], {n, 32}, {m, 0, n}] (* Michael De Vlieger, Nov 06 2015 *)
  • PARI
    Q(N) = {
      my(q = vector(N)); q[1] = [1, 0, 0, 0];
      for (n = 2, N,
        my(m = (sqrtint(8*n+1) - 1)\2);
        q[n] = vector((1 + (m>>2)) << 2); q[n][1] = 1;
        for (k = 2, m, q[n][k] = q[n-k][k] + q[n-k][k-1]));
      return(q);
    };
    apply(vecmax, Q(59))  \\ Gheorghe Coserea, Nov 04 2015

Formula

a(n) = max {Q(n,k), k=1..m}, where m = A003056(n) and Q(n,k) is defined by A008289. - Gheorghe Coserea, Nov 04 2015
a(n) ~ K * exp(Pi*sqrt(n/3)) / n, where K = Pi / (4*sqrt(6*Pi^2 - 72*log(2)^2)) = 0.158271121170... (see A260061). - Gheorghe Coserea, Nov 08 2015

Extensions

More terms from David Wasserman, Jan 23 2002

A131266 Decimal expansion of 2*sqrt(3)*log(2)/Pi.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Sep 28 2007

Keywords

Comments

Also: a constant describing the peak location of the density of states of the minimal difference partition problem in the fermionic case [Comtet et al.].

Examples

			0.76430413884568819720562499904060001690455623711504906130392...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Sqrt[3] Log[4]/Pi, 10, 111][[1]] (* Robert G. Wilson v, Nov 08 2015 *)
  • PARI
    print(2*sqrt(3)*log(2)/Pi);
    
  • PARI
    default(realprecision, 60);
    eval(vecextract(Vec(Str(2*sqrt(3)*log(2)/Pi)), "3..-2"))  \\ Gheorghe Coserea, Nov 07 2015

Formula

Equals lim A257639(n)/sqrt(n) when n tends to infinity.

Extensions

Leading zero removed by R. J. Mathar, Feb 06 2009
Showing 1-2 of 2 results.