A348606 Numbers k such that k and k+1 are both nonexponential abundant numbers.

21735, 76544, 170624, 301664, 345344, 348704, 382304, 739935, 862784, 1218944, 1262624, 1272704, 1314495, 1370655, 1376864, 1539615, 1558304, 1707615, 1718144, 1761375, 1845375, 1890944, 1926015, 2100735, 2132864, 2223584, 2415104, 2463615, 2581215, 2675295, 2747744

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

21735 is a term since A160135(21735) = 21930 > 21735 and A160135(21736) = 23230 > 21736.

Mathematica

esigma[n_] := Times @@ (Sum[First[#]^d, {d, Divisors[Last[#]]}] &) /@ FactorInteger[n]; q[n_] := DivisorSigma[1, n] - esigma[n] > n; Select[Range[1, 3*10^6], q[#] && q[#+1] &]

Crossrefs

Cf. A160135.

Subsequence of A096399 and A348604.

Similar sequences: A318167, A327635, A327942, A331412, A348276.

Sequence in context: A318167 A327635 A274807 * A185863 A265614 A265139

Adjacent sequences: A348603 A348604 A348605 * A348607 A348608 A348609

Keyword

nonn

Author

Amiram Eldar, Oct 25 2021

Status

approved