OFFSET
1,1
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..2148
EXAMPLE
24 is in the sequence since 24 = bsigma(14) = bsigma(15).
MATHEMATICA
f[n_] := Select[Divisors[n], Function[d, CoprimeQ[d, n/d]]]; bsigma[m_] := DivisorSum[m, # &, Last@Intersection[f@#, f[m/#]] == 1 &]; a = {}; b1 = 0; For[k = 0, k < 10^6, k++; b2 = bsigma[k]; If[b1 == b2, a = AppendTo[a, b1]]; b1 = b2]; a (* after Michael De Vlieger at A188999 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Oct 22 2017
STATUS
approved