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 A090695 #9 Oct 31 2017 06:36:52
%S A090695 1,2,3,6,10,12,14,15,20,26,30,40,45,54,60,66,75,80,90,100,105,117,120,
%T A090695 150,180,250,270,280,290,315,320,342,360,390,410,432,440,450,455,480,
%U A090695 495,510,540,560,590,630,645,765,810,980,1080,1170,1220,1305,1430,1530,1860,2235,2310,2670,3120
%N A090695 Integers which are not the sum of 2 integers A and B with AB+1 and AB-1 both primes. In other words, the product cannot be the middle integer of a Twin Prime pair.
%C A090695 Sequence may be finite. Next term after 3120 if it exists must be greater than 867750.
%C A090695 If the sequence can be proved to be finite, then one may surmise that there are infinitely many twin primes and that every integer greater than 3120 and every prime, except 2 and 3, is the sum of 2 integers whose product is the middle number of a twin prime pair.
%C A090695 If there is a term after 3120, it is larger than 4*10^9. - _Giovanni Resta_, Oct 31 2017
%e A090695 15 is a member: 15 is the sum of these pairs of integers: (2+13) (3+12) (4+11) (5+10) (6+9) (7+8). Their products (2*13) (3*12), etc. plus and minus 1 are not primes and therefore the products cannot be the middle integers of Twin Prime sets.
%o A090695 (PARI) isok(n) = {for (a=1, n\2, ab = a*(n-a); if (isprime(ab+1) && isprime(ab-1), return (0));); return (1);} \\ _Michel Marcus_, Jul 12 2013
%Y A090695 Cf. A014574, A091182, A091183.
%K A090695 nonn,fini
%O A090695 1,2
%A A090695 William F. Sindelar (w_sindelar(AT)juno.com), Dec 19 2003