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 A068169 #7 Nov 07 2014 15:50:38 %S A068169 4,41,241,2141,21341,213461,2123461,21123461,211234561,2112343561, %T A068169 21123043561,211230043561,2112030043561,21112030043561, %U A068169 211120030043561,2110120030043561,21101020030043561,211010200230043561,2110102002300430561,21010102002300430561 %N A068169 Define an increasing sequence as follows. Given the first term called the seed (the seed need not have the property of the sequence.). Subsequent terms are defined as obtained by inserting/placing digits (at least one) in the previous term to obtain the smallest number with a given property. This is the growing prime sequence for the seed a(1) = 4. %H A068169 Alois P. Heinz, <a href="/A068169/b068169.txt">Table of n, a(n) for n = 1..300</a> %e A068169 The primes obtained by inserting/placing a digit in a(2) = 41 are 241, 419, 421 etc... a(3)= 241 is the smallest. %Y A068169 Cf. A068166, A068167, A068169. %K A068169 base,nonn %O A068169 1,1 %A A068169 _Amarnath Murthy_, Feb 25 2002 %E A068169 Corrected and extended by _Robert Gerbicz_, Sep 06 2002