|
|
A000334
|
|
Number of 4-dimensional partitions of n.
(Formerly M3858 N1580)
|
|
11
|
|
|
1, 5, 15, 45, 120, 326, 835, 2145, 5345, 13220, 32068, 76965, 181975, 425490, 982615, 2245444, 5077090, 11371250, 25235790, 55536870, 121250185, 262769080, 565502405, 1209096875, 2569270050, 5427963902, 11404408525, 23836421895, 49573316740, 102610460240
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
REFERENCES
|
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
LINKS
|
|
|
EXAMPLE
|
The a(1) = 1 through a(3) = 15 four-dimensional partitions, represented as chains of chains of chains of integer partitions:
(((1))) (((2))) (((3)))
(((11))) (((21)))
(((1)(1))) (((111)))
(((1))((1))) (((2)(1)))
(((1)))(((1))) (((11)(1)))
(((2))((1)))
(((1)(1)(1)))
(((11))((1)))
(((2)))(((1)))
(((1)(1))((1)))
(((11)))(((1)))
(((1))((1))((1)))
(((1)(1)))(((1)))
(((1))((1)))(((1)))
(((1)))(((1)))(((1)))
(End)
|
|
MATHEMATICA
|
trans[x_]:=If[x=={}, {}, Transpose[x]];
levptns[n_, k_]:=If[k==1, IntegerPartitions[n], Join@@Table[Select[Tuples[levptns[#, k-1]&/@y], And@@(GreaterEqual@@@trans[Flatten/@(PadRight[#, ConstantArray[n, k-1]]&/@#)])&], {y, IntegerPartitions[n]}]];
Table[Length[levptns[n, 4]], {n, 8}] (* Gus Wiseman, Jan 24 2019 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,nice
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|