cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 18 results. Next

A108701 Values of n such that n^2-2 and n^2+2 are both prime.

Original entry on oeis.org

3, 9, 15, 21, 33, 117, 237, 273, 303, 309, 387, 429, 441, 447, 513, 561, 573, 609, 807, 897, 1035, 1071, 1113, 1143, 1233, 1239, 1311, 1563, 1611, 1617, 1737, 1749, 1827, 1839, 1953, 2133, 2211, 2283, 2589, 2715, 2721, 2955, 3081, 3093, 3453, 3549, 3555, 3621, 3723, 3807
Offset: 1

Views

Author

John L. Drost, Jun 19 2005

Keywords

Comments

Since x^2 + 2 is divisible by 3 unless x is divisible by 3, all elements are 3 mod 6.
Intersection of A067201 and A028870. - Robert Israel, Sep 11 2014

Examples

			21 is on the list since 21^2 - 2 = 439 and 21^2 + 2 = 443 are primes.
		

References

  • David Wells, Prime Numbers, John Wiley and Sons, 2005, p. 219 (article:'Siamese primes')

Crossrefs

Programs

  • Magma
    [n: n in [3..3600 by 6] | IsPrime(n^2-2) and IsPrime(n^2+2)];  // Bruno Berselli, Apr 15 2011
    
  • Maple
    select(n -> isprime(n^2-2) and isprime(n^2+2), [seq(6*i+3,i=0..1000)]); # Robert Israel, Sep 11 2014
  • Mathematica
    Select[Range[5000], PrimeQ[#^2 - 2] && PrimeQ[#^2 + 2] &] (* Alonso del Arte, Sep 11 2014 *)
  • PARI
    is(n)=isprime(n^2-2)&&isprime(n^2+2) \\ Charles R Greathouse IV, Jul 02 2013

Extensions

Terms corrected by Charles R Greathouse IV, Sep 11 2014

A154831 Numbers n such that n^4-2 is prime.

Original entry on oeis.org

3, 7, 11, 13, 21, 29, 39, 41, 43, 49, 53, 59, 73, 83, 85, 87, 95, 99, 101, 119, 129, 141, 143, 175, 181, 185, 189, 207, 217, 239, 241, 277, 279, 293, 311, 315, 323, 339, 343, 363, 367, 371, 375, 381, 389, 409, 421, 433, 435, 451, 473, 483, 497, 503, 507, 515
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Magma
    [n: n in [1..500] | IsPrime(n^4-2)]; // Vincenzo Librandi, Nov 26 2010
    
  • Mathematica
    lst={};Do[p=n^4-2;If[PrimeQ[p],AppendTo[lst,n]],{n,0,7!}];lst
    Select[Range[600],PrimeQ[#^4-2]&] (* Harvey P. Dale, May 20 2012 *)
  • PARI
    is(n)=isprime(n^4-2) \\ Charles R Greathouse IV, Jul 02 2013

A153974 Numbers n such that n^3 - 3 is prime.

Original entry on oeis.org

2, 4, 8, 10, 14, 16, 26, 34, 38, 40, 74, 80, 106, 110, 116, 124, 136, 158, 178, 184, 190, 206, 224, 230, 238, 256, 274, 280, 316, 320, 338, 340, 386, 410, 428, 446, 458, 464, 470, 484, 496, 530, 544, 550, 556, 590, 626, 634, 644, 646, 674, 710, 718, 728, 730
Offset: 1

Views

Author

Keywords

Comments

2^3 - 3 = 5 is prime, 4^3 - 3 = 61 is prime, ...

Crossrefs

Programs

  • Magma
    [n: n in [2..500] | IsPrime(n^3-3)]; // Vincenzo Librandi, Nov 26 2010
    
  • Mathematica
    a[n_]:=n^x-y;lst={};x=3;y=3;Do[If[PrimeQ[a[n]],AppendTo[lst,n]],{n,0,6!}];lst
    Select[Range[2, 1000], PrimeQ[#^3 - 3] &] (* G. C. Greubel, Sep 01 2016 *)
  • PARI
    is(n)=isprime(n^3-3) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

First two terms 0,1, removed by Zak Seidov, Mar 14 2009

A154832 Primes p such that p^4-2 is also prime.

Original entry on oeis.org

3, 7, 11, 13, 29, 41, 43, 53, 59, 73, 83, 101, 181, 239, 241, 277, 293, 311, 367, 389, 409, 421, 433, 503, 587, 617, 647, 683, 757, 773, 811, 823, 839, 881, 907, 953, 1019, 1093, 1117, 1187, 1249, 1361, 1471, 1481, 1543, 1553, 1571, 1637, 1667, 1747, 1789, 1847
Offset: 1

Views

Author

Keywords

Comments

Primes in A154831.

Crossrefs

Programs

  • Mathematica
    lst={};Do[p=n^4-2;If[PrimeQ[p],If[PrimeQ[n],AppendTo[lst,n]]],{n,0,7!}];lst
    Select[Prime[Range[300]],PrimeQ[#^4-2]&] (* Harvey P. Dale, Nov 24 2018 *)

A154833 Numbers n such that n^5-2 is prime.

Original entry on oeis.org

3, 13, 31, 63, 93, 139, 181, 211, 229, 265, 271, 303, 325, 339, 343, 345, 411, 441, 519, 523, 531, 549, 555, 573, 619, 663, 675, 681, 693, 741, 751, 805, 819, 835, 853, 861, 945, 951, 969, 975, 993, 1063, 1071, 1095, 1119, 1143, 1275, 1281, 1305, 1329
Offset: 1

Views

Author

Keywords

Comments

3^5-2=241 prime, 13^5-2=371291 prime,...

Crossrefs

Programs

  • Magma
    [n: n in [1..500] | IsPrime(n^5-2)]; // Vincenzo Librandi, Nov 26 2010
    
  • Mathematica
    lst={};Do[p=n^5-2;If[PrimeQ[p],AppendTo[lst,n]],{n,0,7!}];lst
    Select[Range[2 10^3], PrimeQ[#^5 - 2] &] (* Vincenzo Librandi, Mar 20 2014 *)
  • PARI
    is(n)=isprime(n^5-2) \\ Charles R Greathouse IV, Feb 17 2017

A154834 Primes p such that p^5 - 2 is also prime.

Original entry on oeis.org

3, 13, 31, 139, 181, 211, 229, 271, 523, 619, 751, 853, 1063, 1483, 1699, 2791, 3361, 3463, 3541, 3769, 4051, 4201, 4801, 4861, 4903, 5521, 5689, 5701, 6163, 6211, 6763, 6823, 6949, 7621, 8059, 8269, 8389, 8419, 8563, 8689, 8713, 9001, 9103, 9319, 10303
Offset: 1

Views

Author

Keywords

Comments

Primes in A154833.

Examples

			3^5 - 2 = 241 is prime,
13^5 - 2 = 371291 is prime, ...
		

Crossrefs

Programs

  • Mathematica
    lst={};Do[p=n^5-2;If[PrimeQ[p],If[PrimeQ[n],AppendTo[lst,n]]],{n,0,7!}];lst
    Select[Prime[Range[1300]],PrimeQ[#^5-2]&] (* Harvey P. Dale, Feb 09 2019 *)

A178251 Primes p such that p^3 - 2 is prime.

Original entry on oeis.org

19, 31, 37, 67, 109, 151, 211, 241, 277, 367, 439, 457, 619, 691, 727, 787, 859, 967, 1087, 1171, 1471, 1489, 1531, 1579, 1951, 2131, 2287, 2791, 2851, 2971, 3061, 3319, 3511, 3547, 3559, 3739, 4129, 4357, 4447, 4507, 4591, 4651, 4789, 4801, 4831, 4951
Offset: 1

Views

Author

Ulrich Krug (leuchtfeuer37(AT)gmx.de), May 24 2010

Keywords

Examples

			6857 = prime(882) = 19^3 - 2, 19 = prime(8) is 1st term.
29789 = prime(3228) = 31^3 - 2, 31 = prime(11) is 2nd term.
		

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(5000) | IsPrime(p^3-2)]; // Vincenzo Librandi, Nov 17 2010
    
  • Mathematica
    Select[Prime[Range[10000]], PrimeQ[#^3 - 2] &] (* Vincenzo Librandi, Mar 20 2014 *)
  • PARI
    list(lim)=my(v=List()); forprime(p=2,lim, if(isprime(p^3-2), listput(v, p))); Vec(v) \\ Charles R Greathouse IV, Feb 08 2016
  • Sage
    a = list(p for p in primes(10000) if is_prime(p**3-2)) # D. S. McNeil, May 25 2010
    

Extensions

Base tag removed by D. S. McNeil, May 25 2010

A038600 Primes of the form n^3 - 2.

Original entry on oeis.org

727, 3373, 6857, 19681, 29789, 50651, 300761, 753569, 970297, 1295027, 1771559, 2146687, 2460373, 3048623, 3442949, 4492123, 6539201, 6751267, 8120599, 8869741, 9393929, 10218311, 13997519, 17373977, 18609623, 19034161, 21253931
Offset: 1

Views

Author

Keywords

Examples

			a(2) = 3373 = 15^3 - 2 = A038599(2)^3 - 2.
		

Crossrefs

Cf. A038599.

Programs

Extensions

Corrected and extended by Jud McCranie, Jan 04 2001

A154933 Numbers k such that k^6 - 2 is prime.

Original entry on oeis.org

3, 11, 17, 35, 37, 47, 49, 59, 67, 77, 99, 123, 127, 133, 139, 155, 161, 169, 173, 187, 195, 213, 225, 231, 237, 241, 245, 247, 253, 275, 279, 297, 319, 325, 367, 373, 381, 383, 385, 399, 411, 425, 431, 469, 507, 511, 523, 541, 545, 553, 569, 585, 589, 609
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    lst={};Do[p=n^6-2;If[PrimeQ[p],AppendTo[lst,n]],{n,1,7!}];lst
  • PARI
    isA154933(n) = isprime(n^6-2) \\ Michael B. Porter, Oct 06 2009

Extensions

a(1) = 0 removed by Amiram Eldar, Apr 04 2020

A154935 Numbers n such that n^7-2 is prime.

Original entry on oeis.org

7, 15, 25, 87, 91, 99, 199, 211, 265, 337, 357, 361, 367, 405, 501, 511, 537, 595, 627, 685, 697, 771, 805, 841, 847, 861, 889, 931, 939, 979, 1035, 1047, 1081, 1125, 1135, 1177, 1225, 1231, 1287, 1315, 1321, 1387, 1425, 1497, 1501, 1627, 1741, 1795, 1807
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Magma
    [n: n in [1..500]|IsPrime(n^7-2)]; // Vincenzo Librandi, Nov 26 2010
    
  • Mathematica
    lst={};Do[p=n^7-2;If[PrimeQ[p],AppendTo[lst,n]],{n,0,7!}];lst
    Select[Range[2*10^3], PrimeQ[#^7 - 2] &] (* Vincenzo Librandi, Mar 20 2014 *)
  • PARI
    is(n)=isprime(n^7-2) \\ Charles R Greathouse IV, Feb 17 2017
Showing 1-10 of 18 results. Next