|
|
A066539
|
|
Difference between larger and smaller terms of n-th amicable pair.
|
|
11
|
|
|
64, 26, 304, 544, 136, 112, 2310, 1120, 13064, 64, 4050, 18018, 8980, 23670, 17550, 784, 11512, 26420, 4480, 4576, 18064, 5720, 84544, 81304, 110852, 43184, 17888, 17150, 11680, 3510, 69296, 76144, 67072, 76592, 9328, 115592, 70592, 61110, 21712
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
REFERENCES
|
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
a(7) = 2310 because the 7th pair of amicable numbers is 12285 and 14595; and 14595 - 12285 = 2310.
|
|
MATHEMATICA
|
With[{s = PositionIndex@Array[DivisorSigma[1, #] &, 10^6]}, Flatten@ Map[Differences, Apply[Join, Map[Function[n, Select[Subsets[Lookup[s, n], {2}], Total@ # == n &]], Sort@ Select[Keys@ s, Length@ Lookup[s, #] > 1 &]]]]] (* Michael De Vlieger, Oct 22 2017 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Robert A. Stump (bee_ess107(AT)yahoo.com), Jan 06 2002
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|