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 16 results. Next

A155211 Numbers n such that n^4+(n+1)^4 is a prime.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 9, 12, 13, 14, 16, 25, 26, 27, 31, 33, 34, 36, 37, 38, 40, 43, 48, 54, 63, 67, 68, 72, 74, 78, 82, 87, 88, 89, 97, 98, 104, 105, 109, 110, 111, 119, 121, 122, 123, 129, 145, 156, 157, 162, 163, 166, 167, 172, 173, 179, 180, 182, 184, 186, 187, 189, 195
Offset: 1

Views

Author

Vincenzo Librandi, Jan 22 2009

Keywords

Crossrefs

Programs

A194155 Primes of the form k^8 + (k+1)^8.

Original entry on oeis.org

257, 2070241, 17995718017, 188386299457, 2505920246017, 3192202523137, 5072985298081, 11905609260481, 21370852274017, 766108283826337, 970961614082017, 2348771079002657, 2887223180589697, 9007197376151521, 55110306149736577, 77802445498340417
Offset: 1

Views

Author

Jonathan Vos Post, Aug 17 2011

Keywords

Comments

Prime 8-dimensional centered cube numbers. This is to dimension 8 as A152913 is to dimension 4.

Examples

			a(2) = 5^8 + (5+1)^8 = 2070241 is prime.
a(3) = 17^8 + (17+1)^8.
a(4) = 23^8 + (23+1)^8.
a(5) = 32^8 + (32+1)^8.
a(6) = 33^8 + (33+1)^8.
		

Crossrefs

Programs

  • Magma
    [ a: n in [0..200] | IsPrime(a) where a is n^8+(n+1)^8 ];  // Vincenzo Librandi, Dec 07 2011
  • Mathematica
    Select[Table[n^8+(n+1)^8,{n,0,900}],PrimeQ] (* Vincenzo Librandi, Dec 07 2011 *)

A078902 Generalized Fermat primes of the form (k+1)^2^m + k^2^m, with m>1.

Original entry on oeis.org

17, 97, 257, 337, 881, 3697, 10657, 16561, 49297, 65537, 66977, 89041, 149057, 847601, 988417, 1146097, 1972097, 2070241, 2522257, 2836961, 3553777, 3959297, 4398577, 5385761, 7166897, 11073217, 17653681, 32530177, 41532497, 44048497
Offset: 1

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Author

T. D. Noe, Dec 12 2002

Keywords

Comments

For k=1, these are the Fermat primes A019434. Is the set of generalized Fermat primes infinite? Conjecture that there are only a finite number of generalized Fermat primes for each value of k. See A077659, which shows that in cases such as k=11, there appear to be no primes. See A078901 for generalized Fermat numbers.
See A080131 for the conjectured number of primes for each k. See A080208 for the least k such that (k+1)^2^n + k^2^n is prime. The largest probable prime of this form discovered to date is the 10217-digit 312^2^12 + 311^2^12.

Crossrefs

Programs

  • Mathematica
    lst3=Select[lst2, PrimeQ[ # ]&] (* lst2 is from A078901 *)

A174156 Numbers n such that n^32+(n+1)^32 is a prime.

Original entry on oeis.org

8, 10, 12, 22, 100, 146, 154, 219, 246, 269, 287, 309, 336, 373, 392, 398, 423, 440, 449, 476, 515, 540, 557, 628, 671, 693, 715, 733, 746, 780, 848, 879, 913, 924, 926, 937, 974, 975, 1130, 1191, 1193, 1198, 1204, 1260, 1272, 1316, 1378, 1400, 1414, 1451
Offset: 1

Views

Author

Vincenzo Librandi, Mar 10 2010

Keywords

Crossrefs

Programs

A174157 Numbers n such that n^64+(n+1)^64 is a prime.

Original entry on oeis.org

95, 302, 443, 546, 755, 850, 878, 962, 983, 988, 1014, 1026, 1349, 1433, 1541, 1711, 1735, 1897, 1901, 1958, 1961, 1966, 2052, 2058, 2070, 2096, 2142, 2167, 2170, 2208, 2333, 2421, 2471, 2490, 2503, 2527, 2571, 2637, 2643, 2813, 2820, 2885, 2994
Offset: 1

Views

Author

Vincenzo Librandi, Mar 10 2010

Keywords

Crossrefs

Programs

  • Magma
    [n: n in [0..2000] | IsPrime(n^64+(n+1)^64)]
  • Mathematica
    lst={}; Do[If[PrimeQ[n^64+(n+1)^64], AppendTo[lst, n]], {n, 3000}]; lst (* Vincenzo Librandi_, Aug 31 2012 *)
    Position[Total/@Partition[Range[3000]^64,2,1],?(PrimeQ[#]&)]//Flatten (* _Harvey P. Dale, Aug 01 2021 *)

A215431 Numbers n such that n^128+(n+1)^128 is a prime.

Original entry on oeis.org

31, 37, 65, 191, 255, 287, 359, 786, 836, 1178, 1229, 1503, 1601, 1609, 2093, 2103, 2254, 2307, 2471, 2934, 2978, 3215, 3220, 3363, 3402, 3705, 3724, 3892, 3894, 3976, 4094, 4478, 4490, 4535, 4566, 4683, 4749, 4752, 4789, 4918, 5064, 6061, 6162, 6167
Offset: 1

Views

Author

Vincenzo Librandi, Aug 31 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Range[7000], PrimeQ[#^128 + (# + 1)^128] &]

A215432 Numbers n such that n^256+(n+1)^256 is a prime.

Original entry on oeis.org

85, 86, 157, 190, 195, 421, 504, 539, 621, 895, 1018, 1159, 1314, 1463, 1482, 1538, 1959, 2036, 2368, 2537, 2618, 2651, 3085, 3148, 3205, 3230, 3347, 3370, 3807, 4061, 4089, 4448, 4641, 4697, 4723, 4851, 4945
Offset: 1

Views

Author

Vincenzo Librandi, Aug 31 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Range[5000], PrimeQ[#^256 + (# + 1)^256] &];

A080208 a(n) is the least k such that the generalized Fermat number (k+1)^(2^n) + k^(2^n) is prime.

Original entry on oeis.org

1, 1, 1, 1, 1, 8, 95, 31, 85, 59, 1078, 754, 311, 3508, 1828, 49957, 22844
Offset: 0

Views

Author

T. D. Noe, Feb 10 2003

Keywords

Comments

The first five terms correspond to the five known Fermat primes. The sequence A078902 lists some of the generalized Fermat primes. Bjorn and Riesel examined generalized Fermat numbers for k <= 11 and n <= 999. The sequence A080134 lists the conjectured number of primes for each k.
For n >= 10, a(n) yields a probable prime. a(13) was found by Henri Lifchitz. It is known that a(14) > 1000.

Examples

			a(5) = 8 because (k+1)^32 + k^32 is prime for k = 8 and composite for k < 8.
		

Crossrefs

Formula

a(n) = A253633(n) - 1.

Extensions

a(14)-a(15) from Jeppe Stig Nielsen, Nov 27 2020
a(16) by Kellen Shenton communicated by Jeppe Stig Nielsen, May 19 2023

A215433 Numbers n such that n^512 + (n+1)^512 is a prime.

Original entry on oeis.org

59, 864, 1455, 1723, 2118, 2172, 2460, 2851, 2916, 2971, 3193, 3476, 3747, 3782, 3795
Offset: 1

Views

Author

Vincenzo Librandi, Aug 31 2012

Keywords

Crossrefs

Programs

A274234 Numbers n such that n^1024 + (n+1)^1024 is prime.

Original entry on oeis.org

1078, 2020, 2471, 3255, 4200, 5135, 5185, 6218, 6823, 7220, 8416, 9003, 9008, 9267, 9396, 9689, 10316, 11150, 11250, 11543, 11652, 12960, 14021, 14201, 16523, 16751, 17006, 17054, 17747, 17874, 18157, 18640, 18834, 20478, 20481, 20794, 21147, 22166, 22608, 22638, 24450, 24677, 24894, 25709
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Jun 15 2016

Keywords

Comments

The first five terms are certified primes, according to: factordb/certoverview.php. The others are probable primes. - Lewis Baxter, Jan 05 2021

Crossrefs

Programs

  • Magma
    [n: n in [1..10000] |IsPrime(n^1024 + (n+1)^1024)]
  • Mathematica
    Select[Range[1, 10000], PrimeQ[#^1024 + (#+1)^1024] &]
  • PARI
    for(n=1, 10000, if(isprime(n^1024 + (n+1)^1024), print1(n, ", ")))
    
Showing 1-10 of 16 results. Next