A214443 Least number k such that (sum of anti-divisors of k)/k >= n.

5, 77, 233415, 105411381075

Offset

1,1

Comments

Least number k such that A066417(k)/k >= n.

Links

Table of n, a(n) for n=1..4.

Jon Perry, The Anti-divisor

Prog

(PARI) a066417(n)=local(x); x=valuation(n, 2); sigma(2*n+1)+sigma(2*n-1)+sigma(n/2^x)*2^(x+1)-6*n-2
for(n=1, 3, for(k=3, 233415, if(a066417(k)/k>=n, print(n " " k); next(2))))

Crossrefs

Cf. A066272, A066417.

Sequence in context: A015056 A326870 A327903 * A015973 A363376 A136578

Adjacent sequences: A214440 A214441 A214442 * A214444 A214445 A214446

Keyword

nonn,more

Author

Donovan Johnson, Aug 08 2012

Status

approved