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.

A227566 Number of partitions of n into distinct parts with boundary size 9.

Original entry on oeis.org

1, 2, 3, 6, 10, 15, 24, 35, 50, 71, 99, 134, 184, 246, 321, 424, 547, 699, 891, 1123, 1400, 1751, 2158, 2648, 3239, 3938, 4751, 5732, 6857, 8174, 9721, 11501, 13535, 15924, 18622, 21728, 25278, 29320, 33873, 39102, 44939, 51542, 58995, 67348, 76654, 87161
Offset: 61

Views

Author

Alois P. Heinz, Jul 16 2013

Keywords

Comments

The boundary size is the number of parts having fewer than two neighbors.

Crossrefs

Column k=9 of A227345, A227551.

A227567 Number of partitions of n into distinct parts with boundary size 10.

Original entry on oeis.org

1, 1, 3, 5, 9, 14, 23, 32, 49, 69, 98, 134, 186, 247, 334, 440, 574, 742, 962, 1218, 1549, 1943, 2430, 3011, 3728, 4564, 5590, 6795, 8227, 9909, 11914, 14223, 16954, 20124, 23795, 28044, 32974, 38592, 45093, 52530, 60991, 70640, 81667, 94095, 108214, 124177
Offset: 75

Views

Author

Alois P. Heinz, Jul 16 2013

Keywords

Comments

The boundary size is the number of parts having fewer than two neighbors.

Crossrefs

Column k=10 of A227345, A227551.

A227568 Largest k such that a partition of n into distinct parts with boundary size k exists.

Original entry on oeis.org

0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10
Offset: 0

Views

Author

Alois P. Heinz, Jul 16 2013

Keywords

Comments

The boundary size is the number of parts having fewer than two neighbors.

Crossrefs

Where records occur: A077043.

Programs

  • Maple
    b:= proc(n, i, t) option remember; `if`(n=0, `if`(t>1, 1, 0),
          `if`(i<1, 0, max(`if`(t>1, 1, 0)+b(n, i-1, iquo(t, 2)),
          `if`(i>n, 0, `if`(t=2, 1, 0)+b(n-i, i-1, iquo(t, 2)+2)))))
        end:
    a:= n-> b(n$2, 0):
    seq(a(n), n=0..100);
  • Mathematica
    b[n_, i_, t_] := b[n, i, t] = If[n == 0, If[t > 1, 1, 0], If[i < 1, 0, Max[If[t > 1, 1, 0] + b[n, i - 1, Quotient[t, 2]], If[i > n, 0, If[t == 2, 1, 0] + b[n - i, i - 1, Quotient[t, 2] + 2]]]]];
    a[n_] := b[n, n, 0];
    Table[a[n], {n, 0, 100}] (* Jean-François Alcover, May 21 2018, translated from Maple *)

Formula

a(n) = max { k : A227345(n,k) > 0 } = max { k : A227551(n,k) > 0 }.
a(n) = floor(2*sqrt(n/3)).
Previous Showing 11-13 of 13 results.