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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..18.

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

Cf. A000203, A007955.

Sequence in context: A193131 A193154 A120061 * A244670 A199146 A137023

Adjacent sequences:  A187939 A187940 A187941 * A187943 A187944 A187945

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Mar 16 2011

EXTENSIONS

a(5)-a(18) from Charles R Greathouse IV, Mar 16 2011

STATUS

approved

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Last modified January 22 19:45 EST 2022. Contains 350504 sequences. (Running on oeis4.)