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 A108016 #14 Aug 16 2024 19:10:36 %S A108016 41,149,5189,39209,186629,213449,1127849,1192469,1695209,2965289, %T A108016 3732629,4359749,4460549,5673929,6718469,7225349,11370389,12446789, %U A108016 12830729,14607689,14837909,16016009,17040389,17288969,20684309 %N A108016 Primes of the form p*(p+2)+6 where p and p+2 are primes. %C A108016 Except for the first term, these numbers end in 9. p can take one of the forms 10k+1, 10k+3, 10k+7 or 10k+9. p = 10k+1 => p*(p+2)+6 = (10k+1)(10k+3)+6 = 10h+9. p can be 10k+1. p = 10k+3 => p+2 = 0 mod 5 not prime. p cannot be 10k+3. p = 10k+7 => p(p+2)+6 = (10k+7)(10k+9)+6 = 10h+9. p can be 10k+7. p = 10k+9 => p(p+2)+6 = (10k+9)*(10k+11)+6 = 0 mod 5 not prime. p cannot be 10k+9. Thus by exhaustion p(p+2)+6 ends in 9. %H A108016 Amiram Eldar, <a href="/A108016/b108016.txt">Table of n, a(n) for n = 1..10000</a> %e A108016 149 = 11*13 + 6 is a term since 11, 13 and 149 are primes. %t A108016 f[p_] := p*(p + 2) + 6; f /@ Select[Range[10^4], And @@ PrimeQ[{#, # + 2, f[#]}] &] (* _Amiram Eldar_, Mar 26 2021 *) %t A108016 Select[Times@@#+6&/@Select[Partition[Prime[Range[1000]],2,1],#[[2]]-#[[1]]==2&],PrimeQ] (* _Harvey P. Dale_, Aug 16 2024 *) %o A108016 (PARI) g(n,k=6) = forprime(x1=3,n, x2=x1+2; if(isprime(x2), p=x1*x2+k; if(isprime(p), print1(p, ", ") ) ) ) %Y A108016 Cf. A001359, A051779. %K A108016 easy,nonn %O A108016 1,1 %A A108016 _Cino Hilliard_, May 31 2005