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.

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A217081 Numbers n such that (n^59-1)/(n-1) is prime.

Original entry on oeis.org

19, 70, 102, 116, 126, 188, 209, 257, 294, 359, 451, 461, 468, 470, 638, 653, 710, 762, 766, 781, 824, 901, 939, 964, 995, 1036, 1047, 1098, 1150, 1211, 1234, 1243, 1256, 1278, 1389, 1401, 1422, 1436, 1454, 1492, 1523, 1639, 1703, 1705, 1826, 1913, 1915, 1978
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Sep 26 2012

Keywords

Crossrefs

Programs

  • Magma
    [n: n in [2..2000] |IsPrime((n^59 - 1) div (n - 1))]; // Vincenzo Librandi, Sep 28 2012
    
  • Mathematica
    Select[Range[2, 2000], PrimeQ[(#^59 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)
  • PARI
    is(n)=isprime((n^59-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from T. D. Noe, Sep 26 2012

A217082 Numbers n such that (n^61-1)/(n-1) is prime.

Original entry on oeis.org

2, 19, 69, 88, 138, 155, 205, 234, 336, 420, 425, 455, 470, 525, 555, 561, 608, 626, 667, 674, 766, 779, 846, 851, 937, 971, 998, 1053, 1055, 1112, 1137, 1263, 1329, 1383, 1445, 1448, 1499, 1544, 1551, 1578, 1640, 1689, 1724, 1750, 1793, 1868, 2143, 2241, 2358
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Sep 26 2012

Keywords

Crossrefs

Programs

  • Magma
    [n: n in [2..2400] |IsPrime((n^61 - 1) div (n - 1))]; // Vincenzo Librandi, Sep 28 2012
    
  • Mathematica
    Select[Range[2, 2400], PrimeQ[(#^61 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)
  • PARI
    is(n)=isprime((n^61-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from T. D. Noe, Sep 26 2012

A217083 Numbers n such that (n^67-1)/(n-1) is prime.

Original entry on oeis.org

46, 122, 238, 304, 314, 315, 328, 332, 346, 372, 382, 426, 440, 491, 496, 510, 524, 528, 566, 638, 733, 826, 1016, 1054, 1071, 1214, 1309, 1338, 1388, 1401, 1457, 1512, 1536, 1582, 1624, 1718, 1773, 1814, 1816, 1825, 1952, 1985, 2021, 2072, 2308, 2349, 2449, 2481
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Sep 26 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Range[2, 2500], PrimeQ[(#^67 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)
  • PARI
    is(n)=isprime((n^67-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from T. D. Noe, Sep 26 2012

A217084 Numbers n such that (n^71-1)/(n-1) is prime.

Original entry on oeis.org

3, 6, 17, 24, 37, 89, 132, 374, 387, 402, 421, 435, 453, 464, 490, 516, 708, 736, 919, 947, 981, 1033, 1067, 1170, 1195, 1253, 1284, 1349, 1385, 1409, 1479, 1709, 1724, 1726, 1735, 1875, 1950, 1984, 2012, 2070, 2124, 2133, 2161, 2194, 2424, 2432, 2459, 2531, 2552
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Sep 26 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Range[2, 1000], PrimeQ[(#^71 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)
  • PARI
    is(n)=isprime((n^71-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from T. D. Noe, Sep 26 2012

A217085 Numbers n such that (n^73-1)/(n-1) is prime.

Original entry on oeis.org

11, 15, 75, 114, 195, 215, 295, 335, 378, 559, 566, 650, 660, 832, 871, 904, 966, 1021, 1112, 1203, 1334, 1433, 1485, 1724, 1822, 1959, 1998, 2115, 2154, 2432, 2465, 2486, 2544, 2559, 2564, 2575, 2611, 2681, 2705, 2735, 2754, 2806, 2880, 3158, 3222, 3306, 3368
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Sep 26 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Range[2, 1000], PrimeQ[(#^73 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)
  • PARI
    is(n)=isprime((n^73-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from T. D. Noe, Sep 26 2012

A217086 Numbers n such that (n^79-1)/(n-1) is prime.

Original entry on oeis.org

22, 112, 140, 158, 170, 254, 271, 330, 334, 354, 390, 483, 528, 560, 565, 714, 850, 888, 924, 929, 933, 935, 970, 1019, 1047, 1141, 1266, 1338, 1359, 1376, 1412, 1485, 1504, 1542, 1598, 1607, 1618, 1747, 1773, 1814, 1843, 2087, 2088, 2100, 2167, 2186, 2233, 2311
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Sep 26 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Range[2, 1000], PrimeQ[(#^79 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)
  • PARI
    is(n)=isprime((n^79-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from T. D. Noe, Sep 26 2012

A217087 Numbers n such that (n^83-1)/(n-1) is prime.

Original entry on oeis.org

41, 146, 386, 593, 667, 688, 906, 927, 930, 1025, 1032, 1111, 1410, 1437, 1638, 1829, 1960, 2045, 2381, 2384, 2618, 2807, 2909, 3059, 3164, 3268, 3370, 3783, 3861, 4043, 4054, 4198, 4284, 4539, 4934, 4968, 4992, 5009, 5047, 5049, 5111, 5217, 5237, 5342, 5367
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Sep 26 2012

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Range[2, 1000], PrimeQ[(#^83 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)
  • PARI
    is(n)=isprime((n^83-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from T. D. Noe, Sep 26 2012

A250177 Numbers n such that Phi_21(n) is prime, where Phi is the cyclotomic polynomial.

Original entry on oeis.org

3, 6, 7, 12, 22, 27, 28, 35, 41, 59, 63, 69, 112, 127, 132, 133, 136, 140, 164, 166, 202, 215, 218, 276, 288, 307, 323, 334, 343, 377, 383, 433, 474, 479, 516, 519, 521, 532, 538, 549, 575, 586, 622, 647, 675, 680, 692, 733, 790, 815, 822, 902, 909, 911, 915, 952, 966, 1025, 1034, 1048, 1093
Offset: 1

Views

Author

Eric Chen, Dec 24 2014

Keywords

Crossrefs

Cf. A008864 (1), A006093 (2), A002384 (3), A005574 (4), A049409 (5), A055494 (6), A100330 (7), A000068 (8), A153439 (9), A250392 (10), A162862 (11), A246397 (12), A217070 (13), A250174 (14), A250175 (15), A006314 (16), A217071 (17), A164989 (18), A217072 (19), A250176 (20), this sequence (21), A250178 (22), A217073 (23), A250179 (24), A250180 (25), A250181 (26), A153440 (27), A250182 (28), A217074 (29), A250183 (30), A217075 (31), A006313 (32), A250184 (33), A250185 (34), A250186 (35), A097475 (36), A217076 (37), A250187 (38), A250188 (39), A250189 (40), A217077 (41), A250190 (42), A217078 (43), A250191 (44), A250192 (45), A250193 (46), A217079 (47), A250194 (48), A250195 (49), A250196 (50), A217080 (53), A217081 (59), A217082 (61), A006315 (64), A217083 (67), A217084 (71), A217085 (73), A217086 (79), A153441 (81), A217087 (83), A217088 (89), A217089 (97), A006316 (128), A153442 (243), A056994 (256), A056995 (512), A057465 (1024), A057002 (2048), A088361 (4096), A088362 (8192), A226528 (16384), A226529 (32768), A226530 (65536), A251597 (131072), A244150 (524287), A243959 (1048576).
Cf. A085398 (Least k>1 such that Phi_n(k) is prime).

Programs

  • Mathematica
    a250177[n_] := Select[Range[n], PrimeQ@Cyclotomic[21, #] &]; a250177[1100] (* Michael De Vlieger, Dec 25 2014 *)
  • PARI
    {is(n)=isprime(polcyclo(21,n))};
    for(n=1,100, if(is(n)==1, print1(n, ", "), 0)) \\ G. C. Greubel, Apr 14 2018

A163268 Primes p such that 1 + p + p^2 + p^3 + p^4 + p^5 + p^6 is prime.

Original entry on oeis.org

2, 3, 5, 13, 17, 31, 61, 73, 89, 149, 163, 251, 349, 353, 461, 523, 599, 647, 863, 941, 947, 1087, 1117, 1229, 1277, 1291, 1297, 1409, 1439, 1489, 1567, 1579, 1609, 1627, 1753, 1783, 1831, 2039, 2131, 2293, 2531, 2609, 2753, 2861, 3037, 3163, 3167, 3299
Offset: 1

Views

Author

Keywords

Comments

Primes in A100330. The generated prime numbers are exactly A194257. [Bernard Schott, Dec 21 2012]

Crossrefs

Programs

  • Maple
    select(p -> isprime(p) and isprime(1+p+p^2+p^3+p^4+p^5+p^6), [2,seq(i,i=3..10000,2)]); # Robert Israel, May 05 2017
  • Mathematica
    f[n_]:=1+n+n^2+n^3+n^4+n^5+n^6; lst={}; Do[p=Prime[n]; If[PrimeQ[f[p]], AppendTo[lst,p]], {n,7!}]; lst
    Select[Prime[Range[500]],PrimeQ[Total[#^Range[0,6]]]&] (* Harvey P. Dale, Jul 13 2022 *)
  • PARI
    n=0;forprime(p=2,10000,isprime((p^7-1)/(p-1))&&print(n++" "p))\\ Zak Seidov, Mar 09 2013

Extensions

Edited (but not checked) by N. J. A. Sloane, Jul 25 2009

A100331 Positive integers n such that n^6 + n^5 + n^4 + n^3 + n^2 + n - 1 is prime.

Original entry on oeis.org

1, 3, 9, 15, 18, 20, 28, 33, 55, 65, 68, 84, 88, 98, 109, 115, 119, 120, 124, 129, 134, 135, 140, 159, 165, 173, 185, 188, 190, 205, 223, 239, 264, 270, 275, 278, 288, 295, 305, 308, 323, 329, 350, 368, 370, 388, 409, 460, 464, 499, 510, 525, 540, 565, 579, 593
Offset: 1

Views

Author

Ray G. Opao, Nov 16 2004

Keywords

Examples

			3 is in the sequence because 3^6 + 3^5 + 3^4 + 3^3 + 3^2 + 3 - 1 = 1091, which is prime.
		

Crossrefs

Cf. A100330.

Programs

  • Magma
    [n: n in [0..700] | IsPrime(n^6+n^5+n^4+n^3+n^2+n-1)]; // Vincenzo Librandi, Dec 13 2015
    
  • Maple
    A100331:=n->`if`(isprime(-1+add(n^i, i=1..6)), n, NULL): seq(A100331(n), n=1..1000); # Wesley Ivan Hurt, Dec 13 2015
  • Mathematica
    Select[Range[600], PrimeQ[Sum[ #^i, {i, 6}] - 1] &] (* Ray Chandler, Nov 17 2004 *)
  • PARI
    is(n) = ispseudoprime(n^6+n^5+n^4+n^3+n^2+n-1) \\ Altug Alkan, Dec 13 2015
Previous Showing 21-30 of 36 results. Next