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%I #7 Dec 24 2019 21:41:50
%S 0,1,1,1,1,2,2,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,
%T 5,5,5,5,5,5,6,7,7,7,7,7,7,7,7,7,7,7,7,7,8,9,9,9,9,9,9,9,9,9,9,9,9,9,
%U 9,9,10,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,12,13,13,13,13
%N Number of numbers m <= n such that 4 equals the first digit after decimal point of square root of n in decimal representation.
%C For n > 1: if A023961(n)=4 then a(n) = a(n-1) + 1, otherwise a(n) = a(n-1).
%C Lim_{n->infinity} a(n)/n = 1/10.
%D G. Pólya and G. Szegő, Problems and Theorems in Analysis I (Springer 1924, reprinted 1972), Part Two, Chap. 4, Sect. 4, Problem 178.
%e a(10) = 2, a(100) = 13, a(1000) = 112, a(10000) = 1030.
%Y Cf. A111850, A111851, A111852, A111853, A111855, A111856, A111857, A111858, A111859, A111894.
%K nonn,base
%O 1,6
%A _Reinhard Zumkeller_, Aug 20 2005
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