OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Wikipedia, Weird number.
EXAMPLE
12110 is a term because it is a weird number, and A033880(12110) = sigma(12110) - 2*12110 = 836 is also a weird number.
MATHEMATICA
With[{weirds = Import["https://oeis.org/a006037/b006037.txt", "Table"][[;; , 2]]}, Select[weirds, (ab = DivisorSigma[1, #] - 2*#) <= Last[weirds] && MemberQ[weirds, ab] &]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Apr 14 2024
STATUS
approved