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!)
A223537 Compressed nim-multiplication table read by antidiagonals. 3
1, 2, 2, 4, 3, 8, 8, 8, 12, 12, 16, 12, 5, 4, 192, 32, 32, 10, 10, 64, 64, 64, 48, 128, 15, 160, 128, 240, 128, 128, 192, 192, 240, 240, 80, 80, 256, 192, 80, 64, 17, 80, 96, 160, 20480, 512, 512, 160, 160, 34, 34, 176, 176, 40960, 40960, 1024 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
A nim-multiplication table (A051775) of size 2^2^n can be compressed to a matrix of size 2^n, using Walsh permutations. As the nim-multiplication tables are submatrices to the bigger ones, also the compressions are submatrices to the bigger ones, leading to this infinite array.
This array is closely related to the nim-multiplication table powers of 2 (A223541). Both arrays can be seen as different views of the same cubic binary tensor.
The diagonal is A001317 (Sierpinski triangle rows read like binary numbers).
The elements of this array are listed in A223539. In the key-matrix A223538 the entries of this array (which become very large) are replaced by the corresponding index numbers of A223539. (Surprisingly, the key-matrix seems to be interesting on its own.)
LINKS
Tilman Piesk, Elements of dual matrix (256 SVGs)
Tilman Piesk, Walsh permutation; nimber multiplication (Wikiversity)
FORMULA
a(m,n) = A223539( A223538(m,n) ).
a(n,n) = A001317(n).
a(1,n) = A134683(n+1).
PROG
( Calculation of this matrix B from matrix A = A223541 with MATLAB: )
B = bin([256 256], 'pre') ;
for m=1:256
B(m, 1:256) = cm2cv( cv2cm( A(m, 1:256) )' ) ;
end
( The functions are linked above. See also the MATLAB code for A223541. )
CROSSREFS
Sequence in context: A005176 A050335 A360686 * A140860 A019681 A241580
KEYWORD
nonn,tabl
AUTHOR
Tilman Piesk, Mar 21 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 June 26 10:15 EDT 2024. Contains 373718 sequences. (Running on oeis4.)