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 A258968 #10 Jun 16 2015 14:22:24 %S A258968 2,3,124,10714158 %N A258968 a(n) is the least positive integer x with A054973(x) = n and A258913(x) < x. %C A258968 Is a(n) well-defined for all n? %C A258968 For n > 1, a(n) belongs to sequence A258931. %C A258968 The terms a(k), for 4 <= k <= 100, if they exist, are larger than 3*10^10. - _Giovanni Resta_, Jun 15 2015 %e A258968 For n=2, sigma(x)=124 for x=48 and 75, and 48+75 = 123 < 124. %e A258968 For n=3, sigma(x)=10714158 for x=3031200, 3417300, and 3987450; and their sum is 10435950 (<10714158). %o A258968 (PARI) a(n)=x=0;while(x++,u=List();for(i=1,x,if(sigma(i)==x,listput(u,i)));if(#u==n&vecsum(Vec(u))<x,return(x))) \\ not optimized because the same sigma values are calculated over and over again instead of being kept %Y A258968 Cf. A054973, A258913, A258931, A007368, A258914. %K A258968 nonn,more %O A258968 0,1 %A A258968 _Jeppe Stig Nielsen_, Jun 15 2015