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 A097493 Primes which are two greater than A097492 terms. 4
 7, 37, 457, 8647, 51315414607 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The next term (17866..79237) has 186 digits. LINKS EXAMPLE a(4) = 8647 = (Product_{k=1..4} A006512(k)) + 2 = 5*7*13*19 + 2 = A097492(4) + 2. - Hartmut F. W. Hoft, Apr 27 2021 MATHEMATICA step[{list_, q_}] := Module[{p=NextPrime[q]}, {Join[list, If[PrimeQ[p+2], {{p, p+2}}, {}]], p}] largerTwin[n_] := Last[Transpose[First[NestWhile[step, {{{3, 5}}, 3}, Length[First[step[#]]]<=n&]]]] a097492[n_] := Rest[FoldList[Times, 1, largerTwin[n]]] a097493[n_] := Select[Map[#+2&, a097492[n]], PrimeQ] a097493[68] (* Hartmut F. W. Hoft, Apr 27 2021 *) PROG (PARI) fu(n) = p=1; for(x=1, n, p*=twinu(x); if(isprime(p+2), print1(p+2", "))) \The n-th upper twin prime twinu(n) = { local(c, x); c=0; x=1; while(c

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Last modified January 24 21:49 EST 2022. Contains 350565 sequences. (Running on oeis4.)