

A085015


Multiplicity of the root 1 in the characteristic polynomial mod 2 of the n X n matrix with entries binomial(i+j,i), 0<=i,j<n.


1



0, 1, 0, 3, 2, 5, 0, 3, 2, 5, 0, 11, 6, 9, 4, 7, 6, 9, 4, 15, 10, 21, 0, 11, 6, 9, 4, 15, 10, 13, 8, 11, 10, 13, 8, 19, 14, 25, 4, 15, 10, 21, 0, 43, 22, 33, 12, 23, 18, 21, 16, 27, 22, 33, 12, 23, 18, 21, 16, 27, 22, 25, 20, 23, 22, 25, 20, 31, 26, 37, 16, 27, 22, 33, 12, 55, 34, 45
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OFFSET

0,4


REFERENCES

R. Bacher and R. Chapman, Symmetric Pascal matrices modulo p, European J. Combin. 25 (2004), no. 4, 459473.


LINKS

Table of n, a(n) for n=0..77.


FORMULA

a(0)=0 and a(2^lk)=(2^l+2*(1)^l)/3k+2*a(k) for 0<=k<=2^(l1).


MAPLE

f := (l, n)>if 2^l<(n) then f(l+1, n); else l fi; fo := n>f(0, n); a := n>if n=0 then 0 else (2^fo(n)+2*(1)^fo(n))/3(2^fo(n)n)+2*a(2^fo(n)n); fi;


CROSSREFS

Sequence in context: A082493 A323912 A021887 * A083254 A068453 A111986
Adjacent sequences: A085012 A085013 A085014 * A085016 A085017 A085018


KEYWORD

easy,nonn


AUTHOR

Roland Bacher, Jun 18 2003


STATUS

approved



