|
|
A194771
|
|
Even numbers that divide the sum of their even divisors.
|
|
3
|
|
|
2, 12, 56, 240, 992, 1344, 16256, 60480, 65520, 1047552, 4357080, 47139840, 67100672, 91065600, 285981696, 919636480, 2758909440, 2952609792, 17179738112, 28364878080, 63996791040, 87722956800, 102002360320, 132867440640, 137438691328
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Since the sum of even divisors of an odd number is zero, every odd number divides its sum of even divisors. - Nathaniel Johnston, Sep 02 2011
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
The divisors of 56 are { 1, 2, 4, 7, 8, 14, 28, 56 } and the sum of the even divisors is 2 + 4 + 8 + 14 + 28 + 56 = 112, hence 56 divides 112, so 56 is in the sequence.
|
|
MAPLE
|
with(numtheory):for n from 1 to 10000000 do if(sigma(n) mod n = 0)then print(2*n):fi:od:
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|