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 A247069 #23 Nov 21 2014 02:05:55 %S A247069 2,2,2,2,3,3,2,2,3,4,3,3,3,2,2,3,4,4,2,3,4,3,3,4,3,5,5,5,5,4,4,4,6,4, %T A247069 5,5,5,6,5,4,6,6,5,4,5,6,7,6,5,5,4,5,5,6,3,5,6,5,6,5,6,3,6,7,5,5,4,5, %U A247069 5,5,6,4,7,4,4,6,6,4,5,7,3,3,3,4,3,5,2,3,5,5,6,7,6,4,7,5,6,5,7,3,8 %N A247069 a(n) = number of distinct primes obtained when inserting 1 anywhere in A069246(n). %C A247069 Among the first 145 terms the largest is a(140)=9 because inserting 1 in 12 places into A069246(140)=18064911343, we get only 9 distinct primes (in the order of their appearances): 118064911343, 181064911343, 180164911343, 180614911343, 180641911343, 180649111343, 180649113143, 180649113413, 180649113431. %H A247069 Zak Seidov, <a href="/A247069/b247069.txt">Table of n, a(n) for n = 1..145</a> %e A247069 a(7)=2 because inserting 1 in 4 possible places into A069246(7)=151 we get only 2 distinct primes, 1151 and 1511. %Y A247069 Cf. A069246. %K A247069 nonn,base %O A247069 1,1 %A A247069 _Zak Seidov_, Nov 17 2014