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A292704
Unitary abundant numbers k such that k+2 is also unitary abundant.
4
1428, 20020, 49740, 63490, 107338, 137170, 142140, 195130, 218218, 315588, 340338, 380380, 382380, 497418, 514668, 555828, 578578, 580578, 602140, 626890, 672978, 711618, 740740, 786828, 795340, 811578, 860860, 862860, 885610, 897258, 904330, 907060, 940938
OFFSET
1,1
LINKS
EXAMPLE
1428 is in the sequence since both 1428 and 1430 are unitary abundant: usigma(1428) = 2880 > 2*1428 and usigma(1430) = 3024 > 2*1430.
MATHEMATICA
usigma[n_]:=If[n==1, 1, Times @@ (1+Power @@@ FactorInteger[n])];
uaQ[n_] := usigma[n] > 2 n; Select[Range@100000, uaQ[#] && uaQ[# + 2] &]
CROSSREFS
Sequence in context: A250582 A260283 A156853 * A321036 A094230 A353080
KEYWORD
nonn
AUTHOR
Amiram Eldar, Sep 21 2017
STATUS
approved