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 A111898 Number of numbers m <= n such that 8 equals the second digit after decimal point of square root of n in decimal representation. 11

%I

%S 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,2,2,2,2,2,2,

%T 2,2,3,3,3,3,3,4,4,4,4,5,5,5,5,5,5,5,6,6,6,7,7,7,8,8,8,8,8,8,8,8,9,9,

%U 9,9,9,10,10,10,10,10,10,10,11,11,11,11,11,11,11,11,11,12,12,13,13,13,13,13

%N Number of numbers m <= n such that 8 equals the second digit after decimal point of square root of n in decimal representation.

%C For n>1: if A111862(n)=8 then a(n)=a(n-1)+1 else a(n)=a(n-1).

%C a(n)/n --> 1/10.

%D G. Polya and G. Szego, Problems and Theorems in Analysis I (Springer 1924, reprinted 1972), Part Two, Chap. 4, Sect. 4, Problem 178.

%e a(10) = 0, a(100) = 13, a(1000) = 94, a(10000) = 1002.

%Y Cf. A111890, A111891, A111892, A111893, A111894, A111895, A111896, A111897, A111899, A111858.

%K nonn,base

%O 1,29

%A _Reinhard Zumkeller_, Aug 20 2005

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