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 A380923 #4 Mar 03 2025 10:09:14 %S A380923 25,245,1250,2401,4235,12250,41503,62500,73205,120050,136045,138985, %T A380923 211750,215215,612500,717409,1176490,1333241,1362053,1856465,2075150, %U A380923 2109107,2351635,2402455,3125000,3660250,3720145,4561235,5330605,5535985,6002500,6802250,6949250 %N A380923 Integers k such that k = Sum k/(p_i + j), where p_i are the prime factors of k (with multiplicity). Case j = -3. %e A380923 138985 = 5*7*11*19^2 = 138985/(5-3) +138985/(7-3) +138985/(11-3) +138985*2/(19-3) %p A380923 with(numtheory): P:=proc(q,h) global k,n,v; v:=[]; %p A380923 for n from 1 to q do if n mod 3>0 then if n=add(n*k[2]/(k[1]+h),k=ifactors(n)[2]) then v:=[op(v),n]; %p A380923 print(n); fi; fi; od; op(v); end: P(6949250,-3); %Y A380923 Cf. A380888, A380889, A380900, A380901, A380924 - A380928. %K A380923 nonn,easy %O A380923 1,1 %A A380923 _Paolo P. Lava_, Mar 03 2025