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 A253897 #6 Jan 25 2015 21:48:40 %S A253897 3,4,5,6,8,9,10,12,14,15,16,18,20,21,22,24,28,30,33,35,36,39,40,44,45, %T A253897 48,50,55,56,60,63,66,70,72,75,77,78,80,84,88,90,91,99,102,104,105, %U A253897 108,112,117,120,126,130,132,135,140,144,150,154,160,165,168,176,180,182,195,198,208 %N A253897 Numbers n such that the sequence A127644 with a(1) = n is conjectured to give a permutation of the natural numbers. %C A253897 See A127644 for more information. %e A253897 a(1) = 3 because A127644 is conjectured to be a permutation of the natural numbers. %o A253897 (PARI) b(r)=v=[r];n=1;while(n<100,p=prod(i=1,#v,v[i]);if(p*n\(vecsum(v)+n)==p*n/(vecsum(v)+n)&&!vecsearch(vecsort(v),n),v=concat(v,n);n=0);n++);#v %o A253897 r=1;while(r<500,if(b(r)>50,print1(r,", "));r++) %Y A253897 Cf. A127644, A252984. %K A253897 nonn %O A253897 1,1 %A A253897 _Derek Orr_, Jan 17 2015