OFFSET
1,2
COMMENTS
The bi-unitary version of A056550.
The corresponding quotients are 1, 2, 13, 28, 38, 43, ... (see the link for more values).
a(32) > 10^13. - Giovanni Resta, May 28 2019
LINKS
Amiram Eldar and Giovanni Resta, Table of n, a(n), A307159(a(n))/a(n) for n=1..31
MATHEMATICA
fun[p_, e_] := If[OddQ[e], (p^(e+1)-1)/(p-1), (p^(e+1)-1)/(p-1)-p^(e/2)]; bsigma[1] = 1; bsigma[n_] := Times @@ (fun @@@ FactorInteger[n]); seq={}; s = 0; Do[s = s + bsigma[n]; If[Divisible[s, n], AppendTo[seq, n]], {n, 1, 10^6}]; seq
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Mar 27 2019
EXTENSIONS
a(23)-a(31) from Giovanni Resta, Apr 20 2019
STATUS
approved