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A258418
Number of partitions of the 4-dimensional hypercube resulting from a sequence of n bisections, each of which splits any part perpendicular to any of the axes, such that each axis is used at least once.
2
336, 9744, 192984, 3279060, 51622600, 779602164, 11499880768, 167393051696, 2419080596520, 34838703973728, 501182126787744, 7212689238965297, 103937431212291680, 1500609318117978064, 21713411768745550544, 314940143510352714144, 4579270473409470432352
OFFSET
4,1
LINKS
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-> T(n, 4):
seq(a(n), n=4..25);
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_] := Sum[A[n, k - i]*(-1)^i*Binomial[k, i], {i, 0, k}];
a[n_] := T[n, 4];
a /@ Range[4, 25] (* Jean-François Alcover, Dec 11 2020, after Alois P. Heinz *)
CROSSREFS
Column k=4 of A255982.
Sequence in context: A223446 A229697 A268626 * A268969 A056933 A289346
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 29 2015
STATUS
approved