A070304 a(n) = number of times n^2*k^2/(n^2+k^2) is an integer as k ranges over 0, 1, 2, ...

1, 2, 1, 2, 2, 2, 1, 2, 1, 6, 1, 2, 1, 2, 3, 2, 2, 2, 1, 7, 1, 2, 1, 2, 2, 4, 1, 2, 1, 8, 1, 2, 1, 3, 2, 2, 2, 2, 2, 7, 1, 2, 1, 2, 3, 2, 1, 2, 1, 7, 2, 4, 1, 2, 2, 2, 1, 4, 1, 9, 1, 2, 1, 2, 5, 2, 1, 4, 1, 7, 1, 2, 1, 3, 3, 2, 1, 5, 1, 7, 1, 3, 1, 2, 4, 2, 1, 2, 1, 8, 1, 2, 1, 2, 2, 2, 1, 2, 1, 8, 2, 4, 1, 4, 3

Offset

1,2

Comments

A018892(n) gives the number of integers of the form nk/(n+k).

Links

Table of n, a(n) for n=1..105.

Prog

(PARI) for(n=1, 150, print1(sum(i=0, n^2, if((n^2*i^2)%(n^2+i^2), 0, 1)), ", "))

Crossrefs

Cf. A066451.

Sequence in context: A167866 A101422 A359938 * A275308 A233138 A214708

Adjacent sequences: A070301 A070302 A070303 * A070305 A070306 A070307

Keyword

easy,nonn

Author

Benoit Cloitre, May 10 2002

Status

approved