A089532 -id:A089532 - cp's OEIS frontend

A023204 Primes p such that 2*p + 3 is also prime.

2, 5, 7, 13, 17, 19, 29, 43, 47, 53, 67, 73, 89, 97, 113, 127, 137, 139, 157, 167, 173, 193, 197, 199, 223, 227, 229, 269, 277, 283, 307, 337, 349, 353, 379, 383, 397, 409, 439, 463, 467, 487, 503, 509, 523, 547, 557, 563, 599, 607, 613, 617, 643, 647, 659, 739, 743, 773

Offset: 1

David W. Wilson

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Cf. A089530, A089531, A089532.

[p: p in PrimesUpTo(1000) | IsPrime(2*p+3)]; // Vincenzo Librandi, Nov 20 2010

A023204 := proc (n) if isprime(n) and isprime(2*n+3) = true then n end if end proc; seq(A023204(n), n=1..1000); # Wesley Ivan Hurt, Jun 28 2014

f[n_]:=PrimeQ[2*n+3]; lst={};Do[p=Prime[n];If[f[p],AppendTo[lst,p]],{n,6!}];lst (* Vladimir Joseph Stephan Orlovsky, Oct 03 2009 *)
Select[Prime[Range[200]],PrimeQ[2#+3]&] (* Harvey P. Dale, May 03 2012 *)

is(n)=isprime(2*n+3)&&isprime(n) \\ Charles R Greathouse IV, Jul 02 2013

A067076 INTERSECT A000040. - R. J. Mathar, Mar 23 2017

A089531 Primes p such that (p-3)/2 is also prime.

Original entry on oeis.org

7, 13, 17, 29, 37, 41, 61, 89, 97, 109, 137, 149, 181, 197, 229, 257, 277, 281, 317, 337, 349, 389, 397, 401, 449, 457, 461, 541, 557, 569, 617, 677, 701, 709, 761, 769, 797, 821, 881, 929, 937, 977, 1009, 1021, 1049, 1097, 1117, 1129, 1201, 1217, 1229, 1237

Offset: 1

Ray Chandler, Nov 07 2003

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Cf. A023204, A089530, A089532.

[p: p in PrimesUpTo(1300) | IsPrime((p-3) div 2)]; // Vincenzo Librandi, Apr 13 2013

Clear[lst,n,f] f[n_]:=PrimeQ[(n-3)/2]; lst={};Do[p=Prime[n];If[f[p],AppendTo[lst,p]],{n,6!}];lst (* Vladimir Joseph Stephan Orlovsky, Oct 13 2009 *)
Select[Prime[Range[300]], PrimeQ[(# - 3) / 2]&] (* Vincenzo Librandi, Apr 13 2013 *)

is(n)=isprime(n) && isprime((n-3)\2) \\ Charles R Greathouse IV, Sep 09 2014

a(n) = 2*A023204(n) + 3.

Comment from Juri-Stepan Gerasimov used as new name (old name moved to formulas). - Charles R Greathouse IV, Sep 09 2014

A089530 A023204 indexed by A000040.

Original entry on oeis.org

1, 3, 4, 6, 7, 8, 10, 14, 15, 16, 19, 21, 24, 25, 30, 31, 33, 34, 37, 39, 40, 44, 45, 46, 48, 49, 50, 57, 59, 61, 63, 68, 70, 71, 75, 76, 78, 80, 85, 90, 91, 93, 96, 97, 99, 101, 102, 103, 109, 111, 112, 113, 117, 118, 120, 131, 132, 137, 139, 140, 144, 147, 149, 154

Offset: 1

Ray Chandler, Nov 07 2003

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Cf. A023204, A089531, A089532.

[n: n in [1..250] | IsPrime(2*NthPrime(n)+3)]; // Vincenzo Librandi, May 02 2016

Select[Range[160], PrimeQ[2 Prime[#] + 3] &] (* Vincenzo Librandi, May 02 2016 *)

a(n)=k such that A023204(n)=A000040(k).

A089529 A089528 indexed by A000040.

Original entry on oeis.org

6, 12, 24, 59, 77, 78, 87, 88, 126, 135, 158, 312, 331, 379, 415, 445, 455, 456, 824, 924, 955, 971, 1069, 1080, 1148, 1226, 1368, 1402, 1480, 1592, 1597, 1826, 1934, 2002, 2014, 2035, 2093, 2187, 2212, 2254, 2315, 2353, 2461, 2587, 2619, 2653, 2766, 2792

Offset: 1

Ray Chandler, Nov 07 2003

nonn

			prime(3)=5, 2*5 + 3 = 13 = prime(6);
prime(4)=7, 2*7 + 3 = 17 = prime(7).

Subsequence of A089532.

Cf. A089526, A089527, A089528.

a(n) = k such that A089528(n) = A000040(k).

a(n) = A000720(A089528(n)). - Michel Marcus, Aug 04 2021

Offset changed to 1 by Jinyuan Wang, Aug 04 2021

cp's OEIS Frontend

A023204 Primes p such that 2*p + 3 is also prime.

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A089531 Primes p such that (p-3)/2 is also prime.

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A089530 A023204 indexed by A000040.

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A089529 A089528 indexed by A000040.

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