A348602 Smaller member of a nonexponential amicable pair: numbers (k, m) such that nesigma(k) = m and nesigma(m) = k, where nesigma(k) is the sum of the nonexponential divisors of k (A160135).

198, 18180, 142310, 1077890, 1156870, 1511930, 1669910, 2236570, 2728726, 3776580, 4246130, 4532710, 5123090, 5385310, 6993610, 7288930, 8619765, 8754130, 8826070, 9478910, 10254970, 14426230, 17041010, 17257695, 21448630, 30724694, 34256222, 35361326, 37784810

Offset

1,1

Comments

The larger counterparts are in A348603.

Links

Table of n, a(n) for n=1..29.

Example

198 is a term since A160135(198) = 204 and A160135(204) = 198.

Mathematica

esigma[n_] := Times @@ (Sum[First[#]^d, {d, Divisors[Last[#]]}] &) /@ FactorInteger[n]; s[n_] := DivisorSigma[1, n] - esigma[n]; seq = {}; Do[m = s[n]; If[m > n && s[m] == n, AppendTo[seq, n]], {n, 1, 1.7*10^6}]; seq

Crossrefs

Cf. A160135, A348601, A348603.

Similar sequences: A002025, A002952, A126165, A126169, A259038, A292980, A322541, A324708, A348343.

Sequence in context: A331098 A290933 A278017 * A270849 A324454 A097731

Adjacent sequences: A348599 A348600 A348601 * A348603 A348604 A348605

Keyword

nonn

Author

Amiram Eldar, Oct 25 2021

Status

approved