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 A287244 #18 Feb 16 2025 08:33:46 %S A287244 4,20,68,88,122,140,188,200,212,220,224,244,254,374,460,490,502,518, %T A287244 550,568,632,688,734,814,832,884,898,908,928,982,1022,1108,1472,1490, %U A287244 1498,1514,1544,1580,1894,1954,2074,2230,2294,2384,2492,2524,2722 %N A287244 Indices n for which concatenation of the numbers from n to n + 9 is prime. %H A287244 Robert Israel, <a href="/A287244/b287244.txt">Table of n, a(n) for n = 1..10000</a> %H A287244 F. Smarandache, <a href="http://www.gallup.unm.edu/~smarandache/Sequences-book.pdf">Sequences of Numbers Involved in Unsolved Problems</a>. %H A287244 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SmarandacheSequences.html">Smarandache Sequences</a> %e A287244 a(1) = 4, since 45678910111213 is prime. %p A287244 filter:= proc(n) isprime(parse(cat($n .. n+9))) end proc: %p A287244 select(filter, 2*[$1..10^4]); # _Robert Israel_, Jan 08 2024 %t A287244 Position[Map[FromDigits@ Flatten@ IntegerDigits@ # &, Partition[Range@ 2800, 10, 1]], p_ /; PrimeQ@ p][[All, 1]] (* _Michael De Vlieger_, May 22 2017 *) %Y A287244 Cf. A030458. %K A287244 base,easy,nonn %O A287244 1,1 %A A287244 _XU Pingya_, May 22 2017