

A166483


Numerator of sequence of ratios of semiprimes and multiples thereof in intervals of length 4*6, 4*6*9, 4*6*9*10,...[A112141] to the length of the interval. See example below. The first few ratios are: 1/4,8/24, 84/216,912/2160,...


0




OFFSET

1,2


COMMENTS

Conjecture: sequences for 2ads, 3ads (composites of 3 primes), 4ads, etc., converge to 1/2, 1/4, 1/8,..., respectively.


LINKS

Table of n, a(n) for n=1..7.


EXAMPLE

Example: For the second ratio, 4*6 is the denominator (product of first two semiprimes), and there 8 multiples of the semiprimes 4,6 in the interval, including those two semiprimes, repetitions (such as 4*3, 2*6) are only counted once. The ratio is then 8/24. The first few analogous ratios for 3ads are: 1/8, 16/96, 336/1728, 7296/34560,...


CROSSREFS

Sequence in context: A050893 A037025 A105063 * A274303 A132586 A208400
Adjacent sequences: A166480 A166481 A166482 * A166484 A166485 A166486


KEYWORD

frac,nonn


AUTHOR

Daniel Tisdale, Oct 14 2009, Oct 16 2009


STATUS

approved



