|
|
A246913
|
|
Numbers n such that sigma(n+sigma(n)) = 6*sigma(n).
|
|
6
|
|
|
831376, 3944688, 16956576, 17843616, 22591296, 25371360, 27870976, 51878736, 58877280, 64641984, 142990848, 164898720, 172821456, 181821024, 204330672, 276371200, 281613024, 301571424, 319848480, 326207700, 342237456, 346502520, 389165568, 389450880, 392110992
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
Number 831376 (with sigma(831376) = 1985984) is in sequence because sigma(831376+sigma(831376)) = sigma(2817360) = 11915904 = 6*1985984.
|
|
PROG
|
(Magma) [n:n in[1..10^7] | SumOfDivisors(n+SumOfDivisors(n))eq 6*SumOfDivisors(n)]
(PARI)
for(n=1, 10^7, if(sigma(n+sigma(n))==6*sigma(n), print1(n, ", "))) \\ Derek Orr, Sep 07 2014
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|