This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A071312 #13 Apr 23 2022 05:35:58 %S A071312 30,70,286,646,1798,3135,3526,3570,6279,7198,8855,8970,10366,10626, %T A071312 10695,11571,16095,16530,17255,17391,20615,20706,20735,20806,23326, %U A071312 24738,24882,26691,28083,31031,36519,36890,38086,38130,41151,41615 %N A071312 Squarefree numbers k such that the largest prime factor of k is equal to the sum of the other prime factors of k. %C A071312 If k = p(1)*p(2)*...p(r) is in the sequence, where p(r) is the largest prime factor, then p(r) = p(1)+p(2)+...+p(r-1). %H A071312 Amiram Eldar, <a href="/A071312/b071312.txt">Table of n, a(n) for n = 1..10000</a> %e A071312 20706 = 2*3*7*17*29 and 2+3+7+17 = 29 hence 20706 is in the sequence. %t A071312 Select[Range[40000], SquareFreeQ[#] && Plus @@ (f = FactorInteger[#][[;;,1]]) == 2 * f[[-1]] &] (* _Amiram Eldar_, Apr 23 2022 *) %o A071312 (PARI) for(n=2,100000,if(issquarefree(n)*sum(i=1,omega(n)-1, component(component(factor(n),1),i))==vecmax(factor(n,1)),print1(n,","))) %Y A071312 Cf. A005117, A071141. %K A071312 easy,nonn %O A071312 1,1 %A A071312 _Benoit Cloitre_, Jun 11 2002