OFFSET
1,1
COMMENTS
Also numbers n such that antisigma(n) modulo sigma(n) = 1. Antisigma(n) = A024816(n) = the sum of the nondivisors of n that are between 1 and n, sigma(n) = A000203(n) = the sum of the divisors of n.
Numbers n such that A232324(n) = 1.
Number 5950 is only squareful number from first 1400 terms (< 50000) of this sequence.
Conjecture: supersequence of A112774 (semiprimes of the form 6n+4).
LINKS
Jaroslav Krizek, Table of n, a(n) for n = 1..1000
EXAMPLE
106 is in sequence because antisigma(106) mod sigma(106) = 5509 mod 162 = 1.
MATHEMATICA
Select[Range[1100], Mod[(#(#+1))/2, DivisorSigma[1, #]]==1&] (* Harvey P. Dale, Sep 08 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Nov 25 2013
STATUS
approved