Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A006237
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A006237 Complexity of tensor sum of n graphs; or spanning trees on n-cube.
(Formerly M3725)
+0
2
1, 1, 4, 384, 42467328, 20776019874734407680, 1657509127047778993870601546036901052416000000, 15385084434981466048710053999438117828156794239305576125756067764471886924847513\ 6000000000000000000000 (list; graph; listen)
OFFSET

0,3

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

G. Kreweras, Complexite et circuits Euleriens dans la sommes tensorielles de graphes, J. Combin. Theory, B 24 (1978), 202-212.

R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see Example 5.6.10.

LINKS

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).

PROGRAM

(PARI) a(n)=2^(2^n-n-1)*prod(k=1, n, k^binomial(n, k))

CROSSREFS

Cf. A006235.

Adjacent sequences: A006234 A006235 A006236 this_sequence A006238 A006239 A006240

Sequence in context: A154569 A038015 A003753 this_sequence A116031 A115049 A158111

KEYWORD

nonn,easy,nice

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), D. E. Knuth

EXTENSIONS

Description expanded 7/95.

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 8 20:39 EST 2009. Contains 166234 sequences.


AT&T Labs Research