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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. 4
389, 449, 3217, 31469, 79757, 127297, 130817, 136417, 145349, 168601, 179957, 193577, 198277, 205069, 207377, 231677, 255617, 287137, 300749, 384001, 409589, 515737, 648437, 689917, 750509, 824069, 854869, 982301, 1103437, 1190237 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = 2*A088119(n) + 3 = 2*A000040(A088066(n)) + 3 = A000040(A089525(n)).
EXAMPLE
p(44)=193, 2*193 + 3 = 389 = p(77);
p(45)=197, 2*197 + 3 = 397 = p(78);
p(46)=199, 2*199 + 3 = 401 = p(79).
MATHEMATICA
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 *)
CROSSREFS
Subsequence of A089528.
Sequence in context: A160030 A006476 A282381 * A106760 A052377 A154624
KEYWORD
nonn
AUTHOR
Ray Chandler, Nov 03 2003
EXTENSIONS
Definition clarified by Harvey P. Dale, Sep 24 2019
Offset changed to 1 by Jinyuan Wang, Aug 04 2021
STATUS
approved

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Last modified March 5 06:12 EST 2024. Contains 370537 sequences. (Running on oeis4.)