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A285624 Triangle read by rows: T(n,k) is the number of vertices with degree k counted over all hypergraphs on n labeled nodes, n>=1,0<=k<=2^(n-1). 0
1, 1, 4, 8, 4, 24, 96, 144, 96, 24, 512, 4096, 14336, 28672, 35840, 28672, 14336, 4096, 512, 163840, 2621440, 19660800, 91750400, 298188800, 715653120, 1312030720, 1874329600, 2108620800, 1874329600, 1312030720, 715653120, 298188800, 91750400, 19660800, 2621440, 163840 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
FORMULA
E.g.f. for column k: x * Sum_{n>=0} binomial(2^n,k)*2^(2^n-1)*x^n/n!.
T(n,k) = n * binomial(2^(n-1),k) * 2^(2^(n-1)-1).
EXAMPLE
1, 1;
4, 8, 4;
24, 96, 144, 96, 24;
512, 4096, 14336, 28672, 35840, 28672, 14336, 4096, 512;
...
MATHEMATICA
nn = 5; Grid[ Map[Select[#, # > 0 &] &,
Drop[Transpose[Table[A[z_] :=Sum[Binomial[2^n, k] 2^(2^n - 1) z^n/n!, {n, 0, nn}]; Range[0, nn]! CoefficientList[Series[ z A[z], {z, 0, nn}], z], {k, 0, 2^(nn - 1)}]], 1]]]
CROSSREFS
Sequence in context: A255293 A019246 A019192 * A356636 A334957 A154912
KEYWORD
nonn,tabf
AUTHOR
Geoffrey Critzer, Apr 22 2017
STATUS
approved

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Last modified March 28 04:13 EDT 2024. Contains 371235 sequences. (Running on oeis4.)