

A215491


Smaller members of regular amicable pairs.


2



220, 2620, 5020, 10744, 17296, 63020, 66928, 67095, 69615, 100485, 122265, 142310, 171856, 176272, 185368, 196724, 308620, 356408, 437456, 503056, 522405, 600392, 609928, 624184, 635624, 643336, 667964, 726104, 898216, 947835, 998104, 1077890, 1154450
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OFFSET

1,1


COMMENTS

An amicable pair (M,K) = (g*m, g*k) with g = gcd(M,K) is called regular if m and k are squarefree, and gcd(g,m) = gcd(g,k) = 1. Otherwise it is called irregular.
Out of the 415442 amicable pairs below 10^17, exactly 330435 of them are regular (79.5%). The ratio appears to slowly increase.  Jonathan Pappas, Jan 31 2022


LINKS



EXAMPLE

The first amicable pair (220, 284) is regular because gcd(220, 284) = 4 with 220 = 4 * (5*11) and 284 = 4 * (71). So 220 belongs to the sequence.
The second amicable pair (1184, 1210) is not regular because gcd(1184, 1210)=2 and 1184 = 2 * (2^4*37). So 1184 does not belong to the sequence.


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



