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.

A258425 Total number of partitions of all hypercubes resulting from a sequence of n bisections, each of which splits any part perpendicular to any of the axes, such that each dimension is used at least once.

Original entry on oeis.org

1, 1, 6, 64, 1020, 21854, 590248, 19268098, 738194780, 32481348812, 1614506203400, 89478362311442, 5471239864890436, 365900668319641264, 26569358218427144576, 2081825562568924254126, 175078869470374599592604, 15730138729512408087404292
Offset: 0

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Author

Alois P. Heinz, May 29 2015

Keywords

Examples

			a(2) = 2 + 4 = 6:
In one dimension:    [||-],  [-||]
.                    .___.   .___.   .___.   .___.
In two dimensions:   |_| |   | |_|   |_|_|   |___|
.                    |_|_|   |_|_|   |___|   |_|_| .
		

Crossrefs

Row sums of A255982.

Programs

  • Maple
    b:= proc(n, k, t) option remember; `if`(t=0, 1, `if`(t=1,
           A(n-1, k), add(A(j, k)*b(n-j-1, k, t-1), j=0..n-2)))
        end:
    A:= proc(n, k) option remember; `if`(n=0, 1,
          -add(binomial(k, j)*(-1)^j*b(n+1, k, 2^j), j=1..k))
        end:
    T:= proc(n, k) option remember;
          add(A(n, k-i)*(-1)^i*binomial(k, i), i=0..k)
        end:
    a:= n-> add(T(n,k), k=0..n):
    seq(a(n), n=0..20);
  • Mathematica
    b[n_, k_, t_] := b[n, k, t] = If[t==0, 1, If[t==1, A[n-1, k], Sum[A[j, k]* b[n-j-1, k, t-1], {j, 0, n-2}]]]; A[n_, k_] := A[n, k] = If[n==0, 1, -Sum[Binomial[k, j]*(-1)^j*b[n+1, k, 2^j], {j, 1, k}]]; T[n_, k_] := T[n, k] = Sum[A[n, k-i]*(-1)^i*Binomial[k, i], {i, 0, k}]; a[n_] := Sum[T[n, k], {k, 0, n}]; Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Feb 07 2017, translated from Maple *)

Formula

a(n) = Sum_{k=0..n} A255982(n,k).
a(n) ~ 2^(2*n-5/8) * n^(n-1) / (exp(n) * (log(2))^(n+1)). - Vaclav Kotesovec, May 30 2015