%I A125520
%S A125520 3,75,825,8835,89235,898335,8992335,89983335,899923335,8999833335,
%T A125520 89999233335,899998333335,8999992333335
%N A125520 a(n) = maximal difference between two distinct n-digit with property 
               that when one of them is typed into a calculator and rotated 180 
               degrees, the other one is seen.
%F A125520 If n is greater than 2 and even, than a(n) is 8 followed by (n / 2) - 
               2 nines followed by another 8 followed by (n / 2) - 1 threes followed 
               by 5. If n is greater than 2 and odd, than a(n) is 8 followed by 
               (n / 2) - 1.5 nines followed by a 2 followed by (n / 2) - 1.5 threes 
               followed by a 5.
%e A125520 a(2) = 75. If someone types 91 into a calculator and rotates it 180 degrees, 
               they will get 16. 91 - 16 = 75. It is easy to check that no larger 
               differences can be obtained.
%Y A125520 Sequence in context: A145675 A162601 A093183 this_sequence A163131 A060869 
               A012491
%Y A125520 Adjacent sequences: A125517 A125518 A125519 this_sequence A125521 A125522 
               A125523
%K A125520 base,nonn
%O A125520 1,1
%A A125520 Tanya Khovanova and Sergei Bernstein (tanyakh(AT)yahoo.com), Dec 29 2006