A005097 -id:A005097 - cp's OEIS frontend

A024702 a(n) = (prime(n)^2 - 1)/24.

1, 2, 5, 7, 12, 15, 22, 35, 40, 57, 70, 77, 92, 117, 145, 155, 187, 210, 222, 260, 287, 330, 392, 425, 442, 477, 495, 532, 672, 715, 782, 805, 925, 950, 1027, 1107, 1162, 1247, 1335, 1365, 1520, 1552, 1617, 1650, 1855, 2072, 2147, 2185, 2262, 2380, 2420, 2625, 2752, 2882, 3015

Offset: 3

Clark Kimberling, Dec 11 1999

Note that p^2 - 1 is always divisible by 24 since p == 1 or 2 (mod 3), so p^2 == 1 (mod 3) and p == 1, 3, 5, or 7 (mod 8) so p^2 == 1 (mod 8). - Michael B. Porter, Sep 02 2016
For n > 3 and m > 1, a(n) = A000330(m)/(2*m + 1), where 2*m + 1 = prime(n). For example, for m = 8, 2*m + 1 = 17 = prime(7), A000330(8) = 204, 204/17 = 12 = a(7). - Richard R. Forberg, Aug 20 2013
For primes => 5, a(n) == 0 or 2 (mod 5). - Richard R. Forberg, Aug 28 2013
The only primes in this sequence are 2, 5 and 7 (checked up to n = 10^7). The set of prime factors, however, appears to include all primes. - Richard R. Forberg, Feb 28 2015
Subsequence of generalized pentagonal numbers (cf. A001318): a(n) = k_n*(3*k_n - 1)/2, for k_n in {1, -1, 2, -2, 3, -3, 4, 5, -5, -6, 7, -7, 8, 9, 10, -10, ...} = A024699(n-2)*((A000040(n) mod 6) - 3)/2, n >= 3. - Daniel Forgues, Aug 02 2016
The only primes in this sequence are indeed 2, 5 and 7. For a prime p >= 5, if both p + 1 and p - 1 contains a prime factor > 3, then (p^2 - 1)/24 = (p + 1)*(p - 1)/24 contains at least 2 prime factors, so at least one of p +  1 and p - 1 is 3-smooth. Let's call it s. Also, If (p^2 - 1)/24 is a prime, then A001222(p^2-1) = 5. Since A001222(p+1) and A001222(p-1) are both at least 2, A001222(s) <= 5 - 2 = 3. From these we can see the only possible cases are p = 7, 11 and 13. - Jianing Song, Dec 28 2018

			For n = 6, the 6th prime is 13, so a(6) = (13^2 - 1)/24 = 168/24 = 7.

Charles R Greathouse IV, Table of n, a(n) for n = 3..10000
Brady Haran and Matt Parker, Squaring Primes, Numberphile video (2018).
Carlos Rivera, Puzzle 1060. Can you find more solutions?, The Prime Puzzles and Problems Connection. [Asks for squares in this sequence]

Subsequence of generalized pentagonal numbers A001318.

Cf. A075888.

A024702:=n->(ithprime(n)^2-1)/24: seq(A024702(n), n=3..70); # Wesley Ivan Hurt, Mar 01 2015

(Prime[Range[3,100]]^2-1)/24 (* Vladimir Joseph Stephan Orlovsky, Mar 15 2011 *)

a(n)=prime(n)^2\24 \\ Charles R Greathouse IV, May 30 2013

is(n)=my(k);issquare(24*n+1,&k)&&isprime(k) \\ Charles R Greathouse IV, May 31 2013

a(n) = (A000040(n)^2 - 1)/24 = (A001248(n) - 1)/24. - Omar E. Pol, Dec 07 2011
a(n) = A005097(n-1)*A006254(n-1)/6. - Bruno Berselli, Dec 08 2011
a(n) = A084920(n)/24. - R. J. Mathar, Aug 23 2013
a(n) = A127922(n)/A000040(n) for n >= 3. - César Aguilera, Nov 01 2019

A105760 Nonnegative numbers k such that 2k+7 is prime.

Original entry on oeis.org

0, 2, 3, 5, 6, 8, 11, 12, 15, 17, 18, 20, 23, 26, 27, 30, 32, 33, 36, 38, 41, 45, 47, 48, 50, 51, 53, 60, 62, 65, 66, 71, 72, 75, 78, 80, 83, 86, 87, 92, 93, 95, 96, 102, 108, 110, 111, 113, 116, 117, 122, 125, 128, 131, 132, 135, 137, 138, 143, 150, 152, 153, 155, 162

Offset: 1

Parthasarathy Nambi, May 04 2005

			If n=0, then 2*0 + 7 = 7 (prime).
If n=15, then 2*15 + 7 = 37 (prime).
If n=27, then 2*27 + 7 = 61 (prime).

Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Tony D. Noe and Jonathan Vos Post, Primes in Fibonacci n-step and Lucas n-step Sequences, J. of Integer Sequences, Vol. 8 (2005), Article 05.4.4.

Cf. A153053 (Numbers n such that 2n+7 is not a prime)
Numbers n such that 2n+k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), this seq(k=7), A155722 (k=9), A101448 (k=11), A153081 (k=13), A089559 (k=15), A173059 (k=17), A153143 (k=19).
Numbers n such that 2n-k is prime: A006254 (k=1), A098090 (k=3), A089253 (k=5), A089192 (k=7), A097069 (k=9), A097338 (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).

Filtered([0..200], k-> IsPrime(2*k+7) ); # G. C. Greubel, May 21 2019

[n: n in [0..200]| IsPrime(2*n+7)]; // Vincenzo Librandi, Dec 21 2010

(Prime[Range[4,100]]-7)/2 (* Vladimir Joseph Stephan Orlovsky, Feb 08 2010 *)
Select[Range[0, 200], PrimeQ[2 # + 7] &] (* Vincenzo Librandi, May 20 2014 *)

is(n)=isprime(2*n+7) \\ Charles R Greathouse IV, Feb 16 2017

[n for n in (0..200) if is_prime(2*n+7) ] # G. C. Greubel, May 21 2019

More terms from Rick L. Shepherd, May 18 2005

A047222 Numbers that are congruent to {0, 2, 3} mod 5.

Original entry on oeis.org

0, 2, 3, 5, 7, 8, 10, 12, 13, 15, 17, 18, 20, 22, 23, 25, 27, 28, 30, 32, 33, 35, 37, 38, 40, 42, 43, 45, 47, 48, 50, 52, 53, 55, 57, 58, 60, 62, 63, 65, 67, 68, 70, 72, 73, 75, 77, 78, 80, 82, 83, 85, 87, 88, 90, 92, 93, 95, 97, 98, 100, 102, 103, 105, 107

Offset: 1

N. J. A. Sloane

Row sum of a triangle where the top value is 2 and every elementary triangle or triple is required to have the values 1,2,2 (see link below). Compare with A008854 where the triple contains 1,2,2 with 1 at the top. - Craig Knecht, Oct 18 2015
Also, numbers k such that k*(k^2+1)/5 is a nonnegative integer. - Bruno Berselli, Jan 16 2016
Conjecture: Apart from 0, the sequence gives the values for c/6, such that an infinite number of primes, p, result in both p^2-c and p^2+c being positive primes, except when c is a square. When c is square solutions exist for c (both within and outside of the a(n) set), but occur at only a single prime p. See A274609. Other c values with only one prime providing a solution occur when p^2-c=3. See A274610. The only remaining c values with single p solutions are: c=2 (with p=3) and c=6 (with p=5). - Richard R. Forberg, Jun 26 2016
See A047363 for case of p^3 +- c. See A005097 and A177735 for observations on the general case p^q +- c. - Richard R. Forberg, Aug 11 2016

Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Craig Knecht, Row sum for the 1,2,2 triangle with 2 at the top.
Index entries for linear recurrences with constant coefficients, signature (1,0,1,-1).

Cf. A008854, A028738, A042965, A047363, A005097.

[n : n in [0..150] | n mod 5 in [0, 2, 3]]; // Wesley Ivan Hurt, Jun 14 2016

A047222 := n -> 2*n - 2 - iquo(n,3): seq(A047222(n), n=1..100); # Wesley Ivan Hurt, Nov 07 2013

Floor[(Range[5, 305, 5] - 4)/3] (* Vladimir Joseph Stephan Orlovsky, Jan 26 2012 *)
Flatten[Table[5n + {0, 2, 3}, {n, 0, 19}]] (* Alonso del Arte, Nov 07 2013 *)
LinearRecurrence[{1, 0, 1, -1}, {0, 2, 3, 5}, 100] (* Vincenzo Librandi, Jun 15 2016 *)

a(n)=(5*n-4)\3 \\ Charles R Greathouse IV, Oct 28 2011

concat(0, Vec(x^2*(2+x+2*x^2)/((1-x)^2*(1+x+x^2)) + O(x^100))) \\ Altug Alkan, Oct 26 2015

From R. J. Mathar, Oct 18 2008: (Start)
G.f.: x^2*(2 + x + 2*x^2)/((1 - x)^2*(1 + x + x^2)).
a(n) = A028738(n-2), 1 < n < 16. (End)
a(n) = floor((5*n-4)/3). - Gary Detlefs, Oct 28 2011
a(n) = 2*n - 2 - floor(n/3). - Wesley Ivan Hurt, Nov 07 2013
From Wesley Ivan Hurt, Jun 14 2016: (Start)
a(n) = a(n-1) + a(n-3) - a(n-4) for n>4.
a(n) = (15*n-15-3*cos(2*n*Pi/3)-sqrt(3)*sin(2*n*Pi/3))/9.
a(3k) = 5k-2, a(3k-1) = 5k-3, a(3k-2) = 5k-5. (End)
a(n) = n - 1 + floor((2n-1)/3). - Wesley Ivan Hurt, Dec 27 2016
Sum_{n>=2} (-1)^n/a(n) = arccoth(3/sqrt(5))/sqrt(5) - log(2)/5. - Amiram Eldar, Dec 10 2021
From Peter Bala, Aug 04 2022: (Start)
a(n) = a(floor(n/2)) + a(1 + ceiling(n/2)) for n >= 4 with a(1) = 0, a(2) = 2 and a(3) = 3.
a(2*n) = a(n) + a(n+1); a(2*n+1) = a(n) + a(n+2). Cf. A008854 and A042965. (End)

A039702 a(n) = n-th prime modulo 4.

Original entry on oeis.org

2, 3, 1, 3, 3, 1, 1, 3, 3, 1, 3, 1, 1, 3, 3, 1, 3, 1, 3, 3, 1, 3, 3, 1, 1, 1, 3, 3, 1, 1, 3, 3, 1, 3, 1, 3, 1, 3, 3, 1, 3, 1, 3, 1, 1, 3, 3, 3, 3, 1, 1, 3, 1, 3, 1, 3, 1, 3, 1, 1, 3, 1, 3, 3, 1, 1, 3, 1, 3, 1, 1, 3, 3, 1, 3, 3, 1, 1, 1, 1, 3, 1, 3, 1, 3, 3, 1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 1, 1, 3, 1, 3, 1, 3, 1, 3

Offset: 1

Clark Kimberling

Except for the first term, A100672(n) = (a(n)-1)/2 = parity of A005097. - Jeremy Gardiner, May 17 2008

Nathaniel Johnston, Table of n, a(n) for n = 1..10000

Cf. A000040, A010873.
Cf. A005097, A100672.
Cf. A039701, A039703-A039706, A100672, A005097, A038194, A007652, A039709-A039715.

a039702 = (`mod` 4) . a000040  -- Reinhard Zumkeller, Feb 20 2012

[p mod 4: p in PrimesUpTo(500)]; // Vincenzo Librandi, May 06 2014

seq(ithprime(n) mod 4, n=1..105); # Nathaniel Johnston, Jun 29 2011

Table[Mod[Prime[n], 4], {n, 105}] (* Nathaniel Johnston, Jun 29 2011 *)
Mod[Prime[Range[100]], 4] (* Vincenzo Librandi, May 06 2014 *)

a(n)=prime(n)%4 \\ Charles R Greathouse IV, Jun 13 2013

Sum_k={1..n} a(k) ~ 2*n. - Amiram Eldar, Dec 11 2024

A089253 Numbers n such that 2n - 5 is a prime.

Original entry on oeis.org

4, 5, 6, 8, 9, 11, 12, 14, 17, 18, 21, 23, 24, 26, 29, 32, 33, 36, 38, 39, 42, 44, 47, 51, 53, 54, 56, 57, 59, 66, 68, 71, 72, 77, 78, 81, 84, 86, 89, 92, 93, 98, 99, 101, 102, 108, 114, 116, 117, 119, 122, 123, 128, 131, 134, 137, 138, 141, 143, 144, 149, 156, 158, 159, 161

Offset: 1

Giovanni Teofilatto, Dec 12 2003

M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988
Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta, UTET, CittaStudiEdizioni, Milano 1997

Shawn A. Broyles, Table of n, a(n) for n = 1..1000

Numbers n such that 2n+k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), A105760 (k=7), A155722 (k=9), A101448 (k=11), A153081 (k=13), A089559 (k=15), A173059 (k=17), A153143 (k=19).

Numbers n such that 2n-k is prime: A006254 (k=1), A098090 (k=3), this sequence (k=5), A089192 (k=7), A097069 (k=9), A097338 (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).

(Prime[Range[2,100]]+5)/2 (* Vladimir Joseph Stephan Orlovsky, Feb 08 2010 *)
Select[Range[2,200],PrimeQ[2#-5]&] (* Harvey P. Dale, Dec 29 2024 *)

a(n)=prime(n+1)\2+3 \\ Charles R Greathouse IV, Oct 30 2012

a(n) = A067076(n) + 4. - Giovanni Teofilatto, Dec 14 2003

Corrected by Ralf Stephan, Mar 03 2004

Further correction from Jeremy Gardiner, Sep 11 2004

A089192 Numbers n such that 2n - 7 is a prime.

Original entry on oeis.org

5, 6, 7, 9, 10, 12, 13, 15, 18, 19, 22, 24, 25, 27, 30, 33, 34, 37, 39, 40, 43, 45, 48, 52, 54, 55, 57, 58, 60, 67, 69, 72, 73, 78, 79, 82, 85, 87, 90, 93, 94, 99, 100, 102, 103, 109, 115, 117, 118, 120, 123, 124, 129, 132, 135, 138, 139, 142, 144, 145, 150, 157, 159, 160

Offset: 1

Giovanni Teofilatto, Dec 08 2003

M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988
Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta, UTET, CittaStudiEdizioni, Milano 1997

Shawn A. Broyles, Table of n, a(n) for n = 1..1000

Numbers n such that 2n+k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), A105760 (k=7), A155722 (k=9), A101448 (k=11), A153081 (k=13), A089559 (k=15), A173059 (k=17), A153143 (k=19).

Numbers n such that 2n-k is prime: A006254 (k=1), A098090 (k=3), A089253 (k=5), this sequence (k=7), A097069 (k=9), A097338 (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).

Select[Range[3,200],PrimeQ[2#-7]&] (* Harvey P. Dale, Aug 24 2014 *)

is(n)=isprime(2*n - 7) \\ Charles R Greathouse IV, Apr 28 2015

Corrected by Ralf Stephan, Mar 03 2004

Further correction from Jeremy Gardiner, Sep 11 2004

A153143 Nonnegative numbers k such that 2k + 19 is prime.

Original entry on oeis.org

0, 2, 5, 6, 9, 11, 12, 14, 17, 20, 21, 24, 26, 27, 30, 32, 35, 39, 41, 42, 44, 45, 47, 54, 56, 59, 60, 65, 66, 69, 72, 74, 77, 80, 81, 86, 87, 89, 90, 96, 102, 104, 105, 107, 110, 111, 116, 119, 122, 125, 126, 129, 131, 132, 137, 144, 146, 147, 149, 156, 159, 164, 165

Offset: 1

Vincenzo Librandi, Dec 19 2008

Or, (p-19)/2 for primes p >= 19.
a(n) = (A000040(n+7) - 19)/2.
a(n) = A005097(n+6) - 9.
a(n) = A067076(n+6) - 8.
a(n) = A089038(n+5) - 7.
a(n) = A105760(n+4) - 6.
a(n) = A101448(n+3) - 4.
a(n) = A089559(n+1) - 2.

			For k = 4, 2*k+19 = 27 is not prime, so 4 is not in the sequence;
for k = 17, 2*k+19 = 53 is prime, so 17 is in the sequence.

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

Cf. A000040 (prime numbers), A153144 (2n+19 is not prime).
Numbers n such that 2n+k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), A105760 (k=7), A155722 (k=9), A101448 (k=11), A153081 (k=13), A089559 (k=15), A173059 (k=17), this seq (k=19).
Numbers n such that 2n-k is prime: A006254 (k=1), A098090 (k=3), A089253 (k=5), A089192 (k=7), A097069 (k=9), A097338 (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).

Filtered([0..200], k-> IsPrime(2*k+19) ); # G. C. Greubel, May 22 2019

[ n: n in [0..165] | IsPrime(2*n+19) ];

(Prime[Range[8,100]]-19)/2 (* Vladimir Joseph Stephan Orlovsky, Feb 08 2010 *)
Select[Range[0, 170], PrimeQ[(2*#)+19]&] (* Vincenzo Librandi, Sep 24 2012 *)

is(n)=isprime(2*n+19) \\ Charles R Greathouse IV, Feb 17 2017

list(lim)=apply(p->p\2-9, primes([19,lim\1*2+19])) \\ Charles R Greathouse IV, Jan 03 2025

[n for n in (0..200) if is_prime(2*n+19) ] # G. C. Greubel, May 22 2019

a(n) ~ (n/2) log n. - Charles R Greathouse IV, Jan 03 2025

Edited, corrected and extended by Klaus Brockhaus, Dec 22 2008

Definition clarified by Zak Seidov, Jul 11 2014

A155722 Numbers k such that 2*k + 9 is prime.

Original entry on oeis.org

1, 2, 4, 5, 7, 10, 11, 14, 16, 17, 19, 22, 25, 26, 29, 31, 32, 35, 37, 40, 44, 46, 47, 49, 50, 52, 59, 61, 64, 65, 70, 71, 74, 77, 79, 82, 85, 86, 91, 92, 94, 95, 101, 107, 109, 110, 112, 115, 116, 121, 124, 127, 130, 131, 134, 136, 137, 142, 149, 151, 152, 154, 161, 164

Offset: 1

Vincenzo Librandi, Jan 25 2009

Subsequence of A001651; A011655(a(n)) = 1. - Reinhard Zumkeller, Jul 09 2010

One less than the associated entry in A105760, two less than in A089038, three less than in A067076. - R. J. Mathar, Jan 05 2011

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

Cf. A155723, A155724.

Numbers h such that 2*h + k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), A105760 (k=7), this seq (k=9), A101448 (k=11), A153081 (k=13), A089559 (k=15), A173059 (k=17), A153143 (k=19).

Filtered([0..200], k-> IsPrime(2*k+9)); # G. C. Greubel, May 21 2019

[n: n in [0..200] | IsPrime(2*n+9)]; // Vincenzo Librandi, Sep 24 2012

(Prime[Range[5, 100]] - 9)/2 (* Vladimir Joseph Stephan Orlovsky, Feb 08 2010 *)
Select[Range[0, 200], PrimeQ[2 # + 9]&] (* Vincenzo Librandi, Sep 24 2012 *)

is(n)=isprime(2*n+9) \\ Charles R Greathouse IV, Jul 12 2016

[n for n in (0..200) if is_prime(2*n+9) ] # G. C. Greubel, May 21 2019

Edited by N. J. A. Sloane, Jun 23 2010

Definition clarified by Zak Seidov, Jul 11 2014

A089559 Nonnegative numbers n such that 2*n + 15 is prime.

Original entry on oeis.org

1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 22, 23, 26, 28, 29, 32, 34, 37, 41, 43, 44, 46, 47, 49, 56, 58, 61, 62, 67, 68, 71, 74, 76, 79, 82, 83, 88, 89, 91, 92, 98, 104, 106, 107, 109, 112, 113, 118, 121, 124, 127, 128, 131, 133, 134, 139, 146, 148, 149, 151, 158, 161, 166

Offset: 1

Ray Chandler, Nov 29 2003

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

Cf. A086303.
Numbers n such that 2n+k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), A105760 (k=7), A155722 (k=9), A101448 (k=11), A153081 (k=13), this seq (k=15), A173059 (k=17), A153143 (k=19).
Numbers n such that 2n-k is prime: A006254 (k=1), A098090 (k=3), A089253 (k=5), A089192 (k=7), A097069 (k=9), A097338 (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).

Filtered([0..200], k-> IsPrime(2*k+15) ); # G. C. Greubel, May 22 2019

[n: n in [0..200] |  IsPrime(2*n+15)]; // Vincenzo Librandi, Apr 28 2014

(Prime[Range[7,100]]-15)/2 (* Vladimir Joseph Stephan Orlovsky, Feb 08 2010 *)
Select[Range[0, 200], PrimeQ[2 # + 15] &] (* Vincenzo Librandi, Apr 28 2014 *)

is(n)=isprime(2*n+15) \\ Charles R Greathouse IV, Apr 28 2015

[n for n in (0..200) if is_prime(2*n+15) ] # G. C. Greubel, May 22 2019

a(n) = A086303(n)/2.

Definition clarified by Zak Seidov, Jul 11 2014

A101448 Nonnegative numbers k such that 2k + 11 is prime.

Original entry on oeis.org

0, 1, 3, 4, 6, 9, 10, 13, 15, 16, 18, 21, 24, 25, 28, 30, 31, 34, 36, 39, 43, 45, 46, 48, 49, 51, 58, 60, 63, 64, 69, 70, 73, 76, 78, 81, 84, 85, 90, 91, 93, 94, 100, 106, 108, 109, 111, 114, 115, 120, 123, 126, 129, 130, 133, 135, 136, 141, 148, 150, 151, 153, 160, 163

Offset: 1

Parthasarathy Nambi, Jan 24 2005

2 is the smallest single-digit prime and 11 is the smallest two-digit prime.

			If n=1, then 2*1 + 11 = 13 (prime).
If n=49, then 2*49 + 11 = 109 (prime).
If n=69, then 2*69 + 11 = 149 (prime).

Shawn A. Broyles, Table of n, a(n) for n = 1..1000

Cf. A101123, A101086.
Numbers n such that 2n+k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), A105760 (k=7), A155722 (k=9), this seq (k=11), A153081 (k=13), A089559 (k=15), A173059 (k=17), A153143 (k=19).
Numbers n such that 2n-k is prime: A006254 (k=1), A098090 (k=3), A089253 (k=5), A089192 (k=7), A097069 (k=9), A097338 (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).

Filtered([0..200], k-> IsPrime(2*k+11) ); # G. C. Greubel, May 21 2019

[n: n in [0..200] | IsPrime(2*n+11)]; // Vincenzo Librandi, Nov 17 2010

select(k-> isprime(11+2*k), [$0..200])[];  # Alois P. Heinz, Jun 02 2022

Select[Range[0, 200], PrimeQ[2# + 11] &] (* Stefan Steinerberger, Feb 28 2006 *)

is(n)=isprime(2*n+11) \\ Charles R Greathouse IV, Apr 29 2015

[n for n in (0..200) if is_prime(2*n+11) ] # G. C. Greubel, May 21 2019

More terms from Stefan Steinerberger, Feb 28 2006

Definition clarified by Zak Seidov, Jul 11 2014

cp's OEIS Frontend

A024702 a(n) = (prime(n)^2 - 1)/24.

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A105760 Nonnegative numbers k such that 2k+7 is prime.

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A047222 Numbers that are congruent to {0, 2, 3} mod 5.

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A039702 a(n) = n-th prime modulo 4.

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A089253 Numbers n such that 2n - 5 is a prime.

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A089192 Numbers n such that 2n - 7 is a prime.

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