login
A348523
Numbers that are both infinitary and noninfinitary abundant numbers.
2
960, 1440, 1800, 2016, 2400, 2940, 3240, 3528, 3780, 4536, 4860, 6720, 7260, 8640, 10080, 10140, 10560, 12096, 12480, 12600, 13860, 14784, 15120, 15360, 15840, 16320, 16380, 16800, 17472, 17640, 18240, 18480, 18720, 18900, 19008, 19800, 20160, 21420, 21600, 21840
OFFSET
1,1
COMMENTS
Apparently, the smallest odd term is 9170790153525.
LINKS
EXAMPLE
960 is a term since A049417(960) = 2040 > 2*960 = 1920 and A348271(960) = 1008 > 960.
MATHEMATICA
f[p_, e_] := Module[{b = IntegerDigits[e, 2], m}, m = Length[b]; Product[If[b[[j]] > 0, 1 + p^(2^(m - j)), 1], {j, 1, m}]]; isigma[1] = 1; isigma[n_] := Times @@ f @@@ FactorInteger[n]; q[n_] := (i = isigma[n]) > 2*n && DivisorSigma[1, n] - i > n; Select[Range[10^4], q]
CROSSREFS
Intersection of A129656 and A348274.
Subsequence of A068403.
Sequence in context: A257417 A137491 A179672 * A158412 A247723 A330496
KEYWORD
nonn
AUTHOR
Amiram Eldar, Oct 21 2021
STATUS
approved