OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
a(2)=24 because 1+2+3+4+8+12-6 = 24 and the subtracted divisor is triangular.
MATHEMATICA
triQ[n_] := IntegerQ @ Sqrt[8n + 1]; Select[Range[1000], MemberQ[Divisors[#], (d = (DivisorSigma[1, #] - 2#)/2)] && triQ[d] &] (* Amiram Eldar, Sep 21 2019 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jason Earls, Aug 17 2005
STATUS
approved