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A006237
Complexity of tensor sum of n graphs; or spanning trees on n-cube.
(Formerly M3725)
5
1, 1, 4, 384, 42467328, 20776019874734407680, 1657509127047778993870601546036901052416000000, 153850844349814660487100539994381178281567942393055761257560677644718869248475136000000000000000000000
OFFSET
0,3
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see Example 5.6.10.
LINKS
Aaron R. Bagheri, Classifying the Jacobian Groups of Adinkras, (2017), HMC Senior Theses.
Frank Harary, John P. Hayes, and Horng-Jyh Wu, A survey of the theory of hypercube graphs, Comput. Math. Appl., 15(4) (1988), 277-289.
Germain Kreweras, Complexité et circuits Eulériens dans les sommes tensorielles de graphes, J. Combin. Theory, B 24 (1978), 202-212. See p. 210, Parag. 4.
Eric Weisstein's World of Mathematics, Hypercube Graph
Eric Weisstein's World of Mathematics, Spanning Tree
FORMULA
a(n) = 2^(2^n-1-n)*1^binomial(n, 1)*2^binomial(n, 2)*...*n^binomial(n, n).
MATHEMATICA
Table[2^(2^n - 1 - n) Product[k^Binomial[n, k], {k, n}], {n, 0, 10}]
PROG
(PARI) a(n)=2^(2^n-n-1)*prod(k=1, n, k^binomial(n, k))
CROSSREFS
Cf. A006235.
Sequence in context: A279525 A003753 A193130 * A181044 A339449 A116031
KEYWORD
nonn,easy,nice
EXTENSIONS
Description expanded July 1995
STATUS
approved