

A111851


Number of numbers m <= n such that 1 equals the first digit after decimal point of square root of n in decimal representation.


11



0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 7, 7, 7, 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, 9, 9, 9, 9, 9, 9, 10, 11
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OFFSET

1,17


COMMENTS

For n > 1: if A023961(n)=1 then a(n) = a(n1) + 1, otherwise a(n) = a(n1).
Lim_{n>infinity} a(n)/n = 1/10.


REFERENCES

G. Pólya and G. Szegő, Problems and Theorems in Analysis I (Springer 1924, reprinted 1972), Part Two, Chap. 4, Sect. 4, Problem 178.


LINKS

Table of n, a(n) for n=1..104.


EXAMPLE

a(10) = 1, a(100) = 9, a(1000) = 99, a(10000) = 990.


CROSSREFS

Cf. A111850, A111852, A111853, A111854, A111855, A111856, A111857, A111858, A111859, A111891.
Sequence in context: A135665 A135662 A111853 * A111852 A133880 A226233
Adjacent sequences: A111848 A111849 A111850 * A111852 A111853 A111854


KEYWORD

nonn,base


AUTHOR

Reinhard Zumkeller, Aug 20 2005


STATUS

approved



