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 A104912 #14 Jun 22 2024 16:09:52 %S A104912 29,47,61,89,97,217,229,299,361,379,389,419,461,463,467,533,637,643, %T A104912 649,701,707,733,749,769,791,847,869,923,943,949,997,1067,1103,1169, %U A104912 1319,1327,1361,1439,1451,1481,1489,1493,1517,1543,1549,1579,1591,1643,1681 %N A104912 Numbers k such that the string 9876543210k is prime. %H A104912 Harvey P. Dale, <a href="/A104912/b104912.txt">Table of n, a(n) for n = 1..1000</a> %t A104912 Select[Range[2000],PrimeQ[9876543210*10^IntegerLength[#]+#]&] (* _Harvey P. Dale_, Jun 22 2024 *) %o A104912 (Magma) [ n: n in [1..1750] | IsPrime(Seqint(Intseq(n) cat [0, 1, 2, 3, 4, 5, 6, 7, 8, 9])) ]; // _Vincenzo Librandi_, Feb 02 2011 %Y A104912 Cf. A104800, A104913. %K A104912 nonn,base %O A104912 1,1 %A A104912 _Zak Seidov_, Mar 29 2005