A054572 Larger members of g-reduced amicable pairs a < b such that sigma(a) = sigma(b) = a + b + gcd(a,b).

182, 184, 435, 435, 801, 885, 1012, 1155, 1162, 1336, 1365, 1534, 1648, 1743, 1989, 2295, 2318, 4527, 4917, 4935, 5229, 5428, 5974, 6128, 7155, 7582, 7708, 8733, 9429, 11115, 11637, 13635, 14378, 15128, 15796, 16252, 17098, 17535, 18124, 20306, 21267, 22869

Offset

1,1

Comments

The lesser counterparts are in A054573.

435 appears twice since it has 2 lesser counterparts, 270 and 280. - Amiram Eldar, Jan 19 2019

Links

Table of n, a(n) for n=1..42.

Example

182 is in the sequence since it is the larger member of the pair (140, 182), and sigma(140) = sigma(182) = 336 = 140 + 182 + gcd(140, 182).

Mathematica

seq={}; Do[s1 = DivisorSigma[1, n]; Do[s2 = DivisorSigma[1, m]; If[s2 == s1 && s2 == n + m + GCD[n, m], AppendTo[seq, n]], {m, 1, n-1}], {n, 1, 1000}]; seq (* Amiram Eldar, Jan 19 2019 *)

Crossrefs

Cf. A000203, A002046, A005820 (perfect numbers analog), A054573.

Sequence in context: A324271 A265997 A204378 * A054985 A124185 A218563

Adjacent sequences: A054569 A054570 A054571 * A054573 A054574 A054575

Keyword

nonn

Author

Yasutoshi Kohmoto

Extensions

Corrected and extended by R. J. Mathar, Oct 19 2006

Name corrected and data corrected and extended by Amiram Eldar, Jan 19 2019

Status

approved