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 A078883 #10 Aug 27 2024 09:15:26
%S A078883 3,5,11,17,71,107,191,431,1151,2591,139967,472391,786431,995327,
%T A078883 57395627,63700991,169869311,4076863487,10871635967,2348273369087,
%U A078883 56358560858111,79164837199871,84537841287167,150289495621631,578415690713087,1141260857376767
%N A078883 Lesser member p of a twin prime pair such that p+1 is 3-smooth.
%H A078883 Ray Chandler, <a href="/A078883/b078883.txt">Table of n, a(n) for n = 1..62</a> (terms < 10^1000)
%F A078883 a(n) = A027856(n)-1 = A078884(n)-2.
%e A078883 A000040(20) = 71 and 71+1 = 72 = 2^3*3^2 = A003586(17) and 71+2 = 73 = A000040(21), therefore 71 is a term.
%t A078883 seq[max_] := Select[Sort[Flatten[Table[2^i*3^j - 1, {i, 1, Floor[Log2[max]]}, {j, 0, Floor[Log[3, max/2^i]]}]]], And @@ PrimeQ[# + {0, 2}] &]; seq[2*10^15] (* _Amiram Eldar_, Aug 27 2024 *)
%Y A078883 Cf. A000040, A001359, A014574, A003586, A027856, A078884.
%Y A078883 Apart from initial terms, same as A059960.
%K A078883 nonn
%O A078883 1,1
%A A078883 _Reinhard Zumkeller_, Dec 11 2002