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 A097379 #14 Apr 22 2025 06:31:50 %S A097379 1,2,4,6,8,10,12,16,18,20,22,24,30,32,36,40,42,44,46,48,50,54,58,60, %T A097379 64,66,70,72,78,80,82,84,88,90,92,96,100,102,106,108,116,120,126,128, %U A097379 130,132,138,140,144,150,156,160,162,164,166,168,176,178,180,184,190,192 %N A097379 Numbers m such that 1+SquareFreeKernel(m) is prime. %H A097379 Amiram Eldar, <a href="/A097379/b097379.txt">Table of n, a(n) for n = 1..10000</a> %F A097379 A076618(a(n)) = A007947(a(n))+1 is prime. %e A097379 m = 100 = (2*5)^2 -> A076618(100) = 1+2*5 = 11 = A000040(5), therefore 100 is a term. %t A097379 Select[Range[200], PrimeQ[1 + Times @@ FactorInteger[#][[;; , 1]]] &] (* _Amiram Eldar_, Feb 01 2024 *) %o A097379 (PARI) is(n) = isprime(1 + vecprod(factor(n)[, 1])); \\ _Amiram Eldar_, Feb 01 2024 %Y A097379 Cf. A007947, A076618, A039787, A097380, A097381, A359213. %K A097379 nonn %O A097379 1,2 %A A097379 _Reinhard Zumkeller_, Aug 11 2004