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A006237 Complexity of tensor sum of n graphs; or spanning trees on n-cube.
(Formerly M3725)
2
1, 1, 4, 384, 42467328, 20776019874734407680, 1657509127047778993870601546036901052416000000, 153850844349814660487100539994381178281567942393055761257560677644718869248475136000000000000000000000 (list; graph; refs; listen; history; text; internal format)
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

Alois P. Heinz, Table of n, a(n) for n = 0..10

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.

D. E. Knuth, Letter to N. J. A. Sloane, Oct. 1994

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

Index entries for sequences related to trees

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 A116031 A115049

Adjacent sequences:  A006234 A006235 A006236 * A006238 A006239 A006240

KEYWORD

nonn,easy,nice

AUTHOR

N. J. A. Sloane, Don Knuth

EXTENSIONS

Description expanded July 1995

STATUS

approved

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Last modified February 18 20:32 EST 2018. Contains 299330 sequences. (Running on oeis4.)