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A111852 Number of numbers m <= n such that 2 equals the first digit after decimal point of square root of n in decimal representation. 11
0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 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, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,18

COMMENTS

For n>1: if A023961(n)=2 then a(n)=a(n-1)+1 else a(n)=a(n-1).

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

REFERENCES

G. Polya and G. Szego, 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..105.

EXAMPLE

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

CROSSREFS

Cf. A111850, A111851, A111853, A111854, A111855, A111856, A111857, A111858, A111859, A111892.

Sequence in context: A135662 A111853 A111851 * A133880 A226233 A059995

Adjacent sequences:  A111849 A111850 A111851 * A111853 A111854 A111855

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Aug 20 2005

STATUS

approved

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Last modified January 18 05:30 EST 2019. Contains 319269 sequences. (Running on oeis4.)