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A111897 Number of numbers m <= n such that 7 equals the second digit after decimal point of square root of n in decimal representation. 11
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 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, 3, 3, 3, 3, 3, 3, 3, 3, 3, 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, 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, 7, 7, 7 (list; graph; refs; listen; history; internal format)
OFFSET

1,20

COMMENTS

For n>1: if A111862(n)=7 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.

EXAMPLE

a(10) = 0, a(100) = 7, a(1000) = 100, a(10000) = 1000.

CROSSREFS

Cf. A111890, A111891, A111892, A111893, A111894, A111895, A111896, A111898, A111899, A111857.

Sequence in context: A108622 A112348 A127321 * A185711 A185712 A135665

Adjacent sequences:  A111894 A111895 A111896 * A111898 A111899 A111900

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Aug 20 2005

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Last modified February 16 13:12 EST 2012. Contains 205909 sequences.