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 A124262 #22 Dec 19 2024 15:05:58 %S A124262 2,19,181,1801,17989,179849,1798487,17984833,179848309,1798483067, %T A124262 17984830667,179848306667,1798483066669,17984830666651, %U A124262 179848306666507,1798483066665031,17984830666650269,179848306666502647,1798483066665026389,17984830666650263887,179848306666502638867 %N A124262 a(n) is the largest prime < 10*a(n-1) for n > 1, with a(1) = 2. %H A124262 Charles R Greathouse IV, <a href="/A124262/b124262.txt">Table of n, a(n) for n = 1..1000</a>, extending and correcting a b-file from Artur Jasinski %t A124262 NestList[NextPrime[10 #, -1]&, 2, 20] (* _Vincenzo Librandi_, Jun 28 2014 *) %o A124262 (PARI) step(k)=precprime(10*k) %o A124262 my(t=1/5); vector(10,n,t=step(t)) \\ _Charles R Greathouse IV_, Sep 14 2015 %Y A124262 Cf. A126031, A126041, A124475. %Y A124262 Sequences for other powers of 10: A124339 (100), A124361 (1000), A124364 (10000), A124362 (100000), A124368 (1000000). %Y A124262 Sequences for initial term k: A124263 (k=3), A124267 (5), A124291 (7), A124290 (11), A124298 (13), A124299 (17), A124336 (23), A124310 (29), A124335 (31), A124337 (37), A124338 (41). %K A124262 nonn %O A124262 1,1 %A A124262 _Artur Jasinski_, Dec 16 2006