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 A076299 #13 Mar 30 2025 16:41:11 %S A076299 2,3,4,5,6,9,15,17,20,21,22,25,27,30,31,33,42,46,54,56,58,60,62,67,72, %T A076299 73,78,81,84,86,87,88,90,93,96,99,100,105,111,112,113,115,119,127,128, %U A076299 133,135,137,145,146,151,152,162,163,164,165,168,170,172,173,176,177 %N A076299 Numbers k such that prime(k) + s*k is prime, s=4. %C A076299 See also A064402 (s=1), A076297 (s=2), A076298 (s=3), A076300 (s=5). %H A076299 G. C. Greubel, <a href="/A076299/b076299.txt">Table of n, a(n) for n = 1..10000</a> %e A076299 4 is OK because p(4) + 4*4 = 7 + 16 = 23 is prime. %t A076299 Select[Range[500], PrimeQ[Prime[#] + 4 #] &] (* _G. C. Greubel_, May 04 2018 *) %o A076299 (Magma) [n: n in [0..500]| IsPrime(NthPrime(n) +4*n)]; // _G. C. Greubel_, May 04 2018 %o A076299 (PARI) select(x->isprime(x), vector(500, n, prime(n) + 4*n), 1) \\ _G. C. Greubel_, May 04 2018 %Y A076299 Cf. A064402, A076297, A076298, A076300. %K A076299 nonn %O A076299 1,1 %A A076299 _Zak Seidov_, Oct 05 2002