login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A232553 Maximal values of permanent on (0,1) square matrices of order n with row and column sums 3. 2
6, 9, 13, 36, 54, 81, 216, 324, 486, 1296, 1944, 2916, 7776, 11664, 17496, 46656, 69984, 104976, 279936, 419904, 629856, 1679616, 2519424, 3779136, 10077696, 15116544, 22674816, 60466176, 90699264, 136048896, 362797056, 544195584, 816293376, 2176782336, 3265173504, 4897760256 (list; graph; refs; listen; history; text; internal format)
OFFSET
3,1
COMMENTS
a(n) attains on subset of symmetric matrices with the main diagonal of 1's.
LINKS
D. Merriell, The maximum permanents in Lambda_n,k, Linear and Multilinear Algebra, 1980, no.9, 81-91.
V. S. Shevelev, Some problems of the theory of enumerating the permutations with restricted position, Journal of Soviet Mathematics, 61 (4) (1992) 2272-2317
FORMULA
a(n) = floor(6^((n-h)/3)*(3/2)^h), where h=0,1 or 2, such that n == h (mod 3).
From Colin Barker, May 27 2016: (Start)
a(n) = 6*a(n-3) for n>5.
G.f.: x^3*(6+9*x+13*x^2+3*x^5) / (1-6*x^3).
(End)
PROG
(PARI) a(n) = h = n%3; floor(6^((n-h)/3)*(3/2)^h); \\ Michel Marcus, Nov 26 2013
(PARI) Vec(x^3*(6+9*x+13*x^2+3*x^5)/(1-6*x^3) + O(x^50)) \\ Colin Barker, May 27 2016
CROSSREFS
Sequence in context: A315974 A176211 A176212 * A155705 A267369 A177891
KEYWORD
nonn,easy
AUTHOR
Vladimir Shevelev, Nov 26 2013
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 08:53 EDT 2024. Contains 371268 sequences. (Running on oeis4.)