OFFSET
1,1
COMMENTS
46495995 = 3*5*7*13*23*1481 is the smallest odd term of this sequence.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000
MATHEMATICA
usigma[1] = 1; usigma[n_] := Times @@ (1 + Power @@@ FactorInteger[n]); Select[Range[10^5], usigma[#] == usigma[2#+1] &] (* Amiram Eldar, Aug 04 2019 *)
PROG
(PARI) a034448(n) = sumdivmult(n, d, if(gcd(d, n/d)==1, d));
isok(n) = a034448(n)==a034448(2*n+1); \\ after Charles R Greathouse IV at A034448
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Aug 01 2017
STATUS
approved