

A111497


Difference between successive terms of floor(10^n/Li(10^n)  1).


0



2, 3, 2, 2, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 2, 2
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OFFSET

1,1


COMMENTS

10^n/Li(10^n)  1) is the ratio of estimated composite numbers less than 10^n to the estimated prime numbers less than 10^n. Conjecture: 2 and 3 are the only numbers in this sequence.


LINKS

Table of n, a(n) for n=1..100.


FORMULA

Li(n) is the logarithmic integral which approximates the number of primes less than n. n Li(n) = Int dt/log(t) 2


PROG

(PARI) LiRatioDiff(m, n) = { local(x, p1, p2, a, b); forstep(x=m, n, 2, p1=10.^x; p2=10^(x+1); a=floor(p1/Li(p1)1); b=floor(p2/Li(p2)1); print1(ba, ", ") ) } Li(x) = \ Logarithmic integral { eint1(log(1/x)) }


CROSSREFS

Sequence in context: A297930 A031217 A064131 * A220554 A208243 A209320
Adjacent sequences: A111494 A111495 A111496 * A111498 A111499 A111500


KEYWORD

easy,nonn


AUTHOR

Cino Hilliard, Nov 16 2005


STATUS

approved



