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 A032622 #13 May 13 2025 11:34:01 %S A032622 2,6,20,26,30,36,44,60,62,66,74,80,86,1004,1034,1046,1086,1094,1104, %T A032622 1136,1142,1194,1200,1206,1214,1224,1250,1262,1266,1290,1292,1296, %U A032622 1320,1326,1332,1346,1350,1352,1356,1364,1370,1380,1404,1416,1434,1472,1496 %N A032622 Numbers k such that k concatenated with k+7 is a prime. %H A032622 Robert Israel, <a href="/A032622/b032622.txt">Table of n, a(n) for n = 1..10000</a> %p A032622 filter:= n -> isprime(n * 10^(1+ilog10(n+7)) + n + 7): %p A032622 select(filter, [seq(i,i=2..10000,2)]); # _Robert Israel_, May 13 2025 %Y A032622 Cf. A032612. %K A032622 nonn,base %O A032622 1,1 %A A032622 _Patrick De Geest_, May 15 1998