cp's OEIS Frontend

A089450 Sequence of primes 2*p(k) + 3 such that 2*p(k) + 3, 2*p(k+1) + 3, 2*p(k+2) + 3 are consecutive primes, where p(i) denotes the i-th prime. Sequence terms are 2*p(k) + 3.

%I A089450 #11 Aug 04 2021 06:02:17
%S A089450 389,449,3217,31469,79757,127297,130817,136417,145349,168601,179957,
%T A089450 193577,198277,205069,207377,231677,255617,287137,300749,384001,
%U A089450 409589,515737,648437,689917,750509,824069,854869,982301,1103437,1190237
%N A089450 Sequence of primes 2*p(k) + 3 such that 2*p(k) + 3, 2*p(k+1) + 3, 2*p(k+2) + 3 are consecutive primes, where p(i) denotes the i-th prime. Sequence terms are 2*p(k) + 3.
%F A089450 a(n) = 2*A088119(n) + 3 = 2*A000040(A088066(n)) + 3 = A000040(A089525(n)).
%e A089450 p(44)=193, 2*193 + 3 = 389 = p(77);
%e A089450 p(45)=197, 2*197 + 3 = 397 = p(78);
%e A089450 p(46)=199, 2*199 + 3 = 401 = p(79).
%t A089450 cpQ[n_]:=Module[{p1=2n+3,p2=2NextPrime[n]+3,p3=2NextPrime[n,2]+3,pr = PrimePi[ 2n+3]},{p1,p2,p3}==Prime[Range[pr,pr+2]]]; 2#+3&/@ Select[ Prime[ Range[50000]],cpQ] (* _Harvey P. Dale_, Sep 24 2019 *)
%Y A089450 Subsequence of A089528.
%Y A089450 Cf. A088066, A088119, A089525.
%K A089450 nonn
%O A089450 1,1
%A A089450 _Ray Chandler_, Nov 03 2003
%E A089450 Definition clarified by _Harvey P. Dale_, Sep 24 2019
%E A089450 Offset changed to 1 by _Jinyuan Wang_, Aug 04 2021