OFFSET
1,1
COMMENTS
LINKS
Bhabesh Das and Helen K. Saikia, Identities for Near and Deficient Hyperperfect Numbers, Indian Journal in Number Theory, Vol. 3 (2016), pp. 124-134, alternative link.
EXAMPLE
35 is in the sequence since sigma(35) = 48 and 3*35/2 + 1/2 - 48 = 5 is a proper divisor of 35.
MATHEMATICA
aQ[n_]:=Module[{d = 3n/2+1/2-DivisorSigma[1, n]}, d>0 && d!=n && IntegerQ[d] && Divisible[n, d]]; Select[Range[2, 1000000], aQ]
PROG
(PARI) isok(n) = (n % 2) && (k = (3*n+1)/2 - sigma(n)) && !(n % k) && (k != n); \\ Michel Marcus, Jun 07 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Jun 06 2018
STATUS
approved