A048880 - OEIS

%I #23 Jun 24 2021 19:20:15

%S 17,37,79,223,439,4759,22501,32401,53359,57601,60493,72901,77839,

%T 95479,99223,159199,164011,176401,194479,239119,324901,378223,416023,

%U 497011,680623,756853,804511,1115113,1664101,1742401,2223079

%N Primes of form pq+2 where p and q are consecutive primes.

%C All terms > 17 are congruent to 1 mod 6. - _Zak Seidov_, Dec 03 2010

%H T. D. Noe, <a href="/A048880/b048880.txt">Table of n, a(n) for n=1..1000</a>

%F a(n) = 6*A342564(n-1) + 1 for n >= 2. - _Hugo Pfoertner_, Jun 24 2021

%e 487*491+2=239119.

%p with (numtheory): for n from 1 to 1000 do if (tau(ithprime(n)*ithprime(n+1)+2)=2) then print(ithprime(n),ithprime(n+1),ithprime(n)*ithprime(n+1)+2); fi; od;

%t Reap[Do[If[PrimeQ[p=Prime[k]*Prime[k+1]+2],Sow[p]],{k,1,430}]][[2,1]] (* Zak Seidov Dec 03 2010 *)

%Y Cf. A051507, A123921, A342564.

%K easy,nonn

%O 1,1

%A Herman H. Rosenfeld (herm3(AT)pacbell.net)

%E Corrected and extended by Joe DeMaio (jdemaio(AT)kennesaw.edu).