

A117582


For successive primes p, the number of ratios of the form n^2/(n^21) which factor into primes less than or equal to p.


2



0, 2, 5, 10, 15, 24, 34, 46, 57, 74, 90, 114, 141
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

By a theorem of Størmer, the number of ratios m/(m1) factoring into primes only up to p is finite. A proportion of these have square denominators.


LINKS

Table of n, a(n) for n=0..12.
E. F. Ecklund and R. B. Eggleton, Prime factors of consecutive integers, Amer. Math. Monthly, 79 (1972), 10821089.
D. H. Lehmer, On a problem of Størmer, Ill. J. Math., 8 (1964), 5779.


CROSSREFS

Cf. A002071, A117583.
Sequence in context: A163059 A099738 A064513 * A002134 A243971 A062472
Adjacent sequences: A117579 A117580 A117581 * A117583 A117584 A117585


KEYWORD

hard,nonn


AUTHOR

Gene Ward Smith, Apr 02 2006


STATUS

approved



