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 A224217 #7 Sep 23 2020 19:28:29 %S A224217 4,10,34,46,70,76,94,112,124,160,166,196,202,244,256,292,334,340,370, %T A224217 412,430,454,460,490,502,514,532,550,574,586,592,622,664,712,724,754, %U A224217 766,784,790,796,802,832,850,874,886,916,952,994 %N A224217 Numbers b such that b^2 + 4*b + 9 is prime. %C A224217 Inspired by Sun's conjecture in A224197: Also, bases b such that the number (with digits) [1;4;9] in base b is prime. %C A224217 All terms are congruent to 4 (mod 6), i.e., a(n) = 4 + 6 x(n) with x=(0, 1, 5, 7, 11, 12, 15, 18, 20, 26, 27, 32, 33, 40, 42, 48, 55, 56, 61, 68, 71, 75, 76,...) %t A224217 Select[Range[1000],PrimeQ[#^2+4#+9]&] (* _Harvey P. Dale_, Sep 23 2020 *) %K A224217 nonn %O A224217 1,1 %A A224217 _M. F. Hasler_, Apr 01 2013