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A187942
Numbers n of the form (product of divisors of k)/(sum of divisors of k) for some k.
0
1, 3, 392, 11250, 131769, 501126, 15780962, 131079601, 1568294784, 30261936128, 2966827112704, 119439360000000, 238660389865072, 6566468639062500, 39226324511250000, 73141605808805632, 162778775259375000, 282080144308712092
OFFSET
1,2
PROG
(PARI) A007955(n)=if(issquare(n, &n), n^numdiv(n^2), n^(numdiv(n)/2))
v=[]; for(n=1, 1e4, if(a(n)%sigma(n)==0, v=concat(v, A007955(n)/sigma(n)))); vecsort(v, , 8) \\ Charles R Greathouse IV, Mar 16 2011
CROSSREFS
Sequence in context: A193131 A193154 A120061 * A244670 A199146 A137023
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(5)-a(18) from Charles R Greathouse IV, Mar 16 2011
STATUS
approved