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%I #12 May 27 2024 22:59:26
%S 0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,-1,0,1,2,3,4,5,6,7,8,-4,-3,
%T -2,-1,0,1,2,3,4,5,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,-16,-15,-14,-13,-12,
%U -11,-10,-9,-8,-7,-25,-24,-23,-22,-21,-20,-19,-18,-17,-16,-36,-35,-34,-33,-32,-31,-30
%N Determinants of Hankel matrices corresponding to digits of numbers with an odd number of digits.
%H Robert Israel, <a href="/A373102/b373102.txt">Table of n, a(n) for n = 1..10000</a>
%F a((21 + 100^(i + 1))/11 + 100*x + z + 1) = a((21 + 100^(i + 1))/11 + 100*x + z) + a((21 + 100^i)/11 + x) for 0 <= x < 9 * 10^i, 0 <= z <= 98 with z !== 9 (mod 10).
%e a(13) = 2 because the 13th number with an odd number of digits is 102 and the Hankel matrix
%e [ 1 0 ]
%e [ 0 2 ]
%e formed from the digits 1,0,2 has determinant 2.
%p f:= proc(n)
%p Determinant(HankelMatrix(convert(n,base,10)))
%p end proc;
%p map(f, [$0..9, $100..999]);
%Y Cf. A373066.
%K sign,base,look
%O 1,3
%A _Robert Israel_, May 23 2024
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