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A244571
Smallest prime p >= prime(n) such that p*prime(n)-2 is prime.
5
3, 5, 7, 23, 13, 23, 19, 41, 29, 61, 37, 59, 43, 47, 71, 107, 61, 73, 71, 97, 109, 113, 89, 157, 113, 103, 107, 127, 167, 127, 131, 149, 139, 179, 163, 163, 181, 227, 173, 251, 199, 191, 223, 257, 229, 211, 223, 233, 271, 233, 239, 271, 281, 257, 443, 389, 373
OFFSET
2,1
COMMENTS
See comment in A244572.
LINKS
V. Shevelev, Theorems on twin primes-dual case, arXiv:0912.4006 [math.GM], 2009-2014. Sections 10, 14.
MATHEMATICA
a[n_] := For[p = Prime[n], True, p = NextPrime[p], If[PrimeQ[p Prime[n] - 2], Return[p]]];
Table[a[n], {n, 2, 60}] (* Jean-François Alcover, Nov 18 2018 *)
PROG
(PARI) s=[]; for(n=2, 100, p=q=prime(n); while(!isprime(p*q-2), p=nextprime(p+1)); s=concat(s, p)); s \\ Colin Barker, Jun 30 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Jun 30 2014
EXTENSIONS
More terms from Peter J. C. Moses, Jun 30 2014
STATUS
approved