|
%I #10 Sep 08 2021 21:15:59
%S 1428,20020,49740,63490,107338,137170,142140,195130,218218,315588,
%T 340338,380380,382380,497418,514668,555828,578578,580578,602140,
%U 626890,672978,711618,740740,786828,795340,811578,860860,862860,885610,897258,904330,907060,940938
%N Unitary abundant numbers k such that k+2 is also unitary abundant.
%H Amiram Eldar, <a href="/A292704/b292704.txt">Table of n, a(n) for n = 1..10000</a>
%e 1428 is in the sequence since both 1428 and 1430 are unitary abundant: usigma(1428) = 2880 > 2*1428 and usigma(1430) = 3024 > 2*1430.
%t usigma[n_]:=If[n==1, 1, Times @@ (1+Power @@@ FactorInteger[n])];
%t uaQ[n_] := usigma[n] > 2 n; Select[Range@100000, uaQ[#] && uaQ[# + 2] &]
%Y Cf. A034683, A096399.
%K nonn
%O 1,1
%A _Amiram Eldar_, Sep 21 2017
|
