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.

Previous Showing 31-38 of 38 results.

A260564 Numbers n such that (n^53+1)/(n+1) is prime.

Original entry on oeis.org

10, 14, 40, 57, 111, 119, 406, 447, 475, 620, 646, 839, 848, 866, 909, 997, 1086, 1095, 1180, 1318, 1319, 1332, 1418, 1447, 1472, 1534, 1617, 1681, 1684, 1735, 1788, 1955, 2037, 2118, 2120, 2163, 2169, 2170, 2390, 2407, 2440, 2498, 2700, 2709, 2716, 2761, 2999
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Jul 29 2015

Keywords

Links

Crossrefs

Cf. A055494, A246392, A250174, A250178, A250181, A250185, A250187, A250193, A260558-A260573.

Programs

  • Magma
    [n: n in [1..10000] |IsPrime((n^53 + 1) div (n + 1))]
  • Mathematica
    Select[Range[1, 10000], PrimeQ[(#^53 + 1)/(# + 1)] &]
  • PARI
    for(n=1,10000, if(isprime((n^53+1)/(n+1)), print1(n,", ")))

A260565 Numbers n such that (n^59+1)/(n+1) is prime.

Original entry on oeis.org

6, 9, 25, 46, 89, 92, 109, 133, 136, 140, 167, 173, 213, 239, 255, 277, 337, 350, 359, 553, 554, 586, 594, 599, 639, 692, 710, 815, 860, 864, 1015, 1030, 1050, 1094, 1106, 1110, 1112, 1195, 1199, 1211, 1216, 1260, 1347, 1363, 1370, 1459, 1476, 1477, 1507, 1541
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Jul 29 2015

Keywords

Links

Crossrefs

Cf. A055494, A246392, A250174, A250178, A250181, A250185, A250187, A250193, A260558-A260573.

Programs

  • Magma
    [n: n in [1..10000] |IsPrime((n^59 + 1) div (n + 1))]
  • Mathematica
    Select[Range[1, 10000], PrimeQ[(#^59 + 1)/(# + 1)] &]
  • PARI
    for(n=1,10000, if(isprime((n^59+1)/(n+1)), print1(n,", ")))

A260566 Numbers n such that (n^61+1)/(n+1) is prime.

Original entry on oeis.org

2, 7, 70, 178, 208, 251, 274, 276, 290, 326, 328, 350, 413, 452, 552, 558, 594, 595, 605, 607, 626, 787, 791, 801, 905, 971, 1019, 1091, 1117, 1140, 1198, 1241, 1274, 1357, 1428, 1462, 1604, 1647, 1654, 1705, 1717, 1908, 1987, 2061, 2109, 2161, 2309, 2372, 2450
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Jul 29 2015

Keywords

Links

Crossrefs

Cf. A055494, A246392, A250174, A250178, A250181, A250185, A250187, A250193, A260558-A260573.

Programs

  • Magma
    [n: n in [1..10000] |IsPrime((n^61 + 1) div (n + 1))]
  • Mathematica
    Select[Range[1, 10000], PrimeQ[(#^61 + 1)/(# + 1)] &]
  • PARI
    for(n=1,10000, if(isprime((n^61+1)/(n+1)), print1(n,", ")))

A260567 Numbers n such that (n^67+1)/(n+1) is prime.

Original entry on oeis.org

5, 10, 23, 33, 40, 54, 193, 326, 330, 364, 375, 382, 388, 404, 438, 449, 562, 625, 626, 683, 700, 765, 797, 807, 1001, 1017, 1136, 1181, 1216, 1242, 1249, 1254, 1286, 1386, 1412, 1482, 1581, 1656, 1748, 1832, 1873, 1921, 2017, 2038, 2061, 2166, 2193, 2204, 2253
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Jul 29 2015

Keywords

Links

Crossrefs

Cf. A055494, A246392, A250174, A250178, A250181, A250185, A250187, A250193, A260558-A260573.

Programs

  • Magma
    [n: n in [1..10000] |IsPrime((n^67 + 1) div (n + 1))]
  • Mathematica
    Select[Range[1, 10000], PrimeQ[(#^67 + 1)/(# + 1)] &]
  • PARI
    for(n=1,10000, if(isprime((n^67+1)/(n+1)), print1(n,", ")))

A260568 Numbers n such that (n^71+1)/(n+1) is prime.

Original entry on oeis.org

46, 94, 99, 189, 226, 236, 244, 372, 387, 390, 409, 410, 424, 442, 478, 540, 574, 608, 611, 644, 653, 695, 707, 846, 868, 1036, 1248, 1336, 1374, 1395, 1418, 1424, 1549, 1665, 1737, 1856, 1866, 1880, 1917, 1937, 2105, 2114, 2126, 2141, 2166, 2202, 2217, 2274
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Jul 29 2015

Keywords

Links

Crossrefs

Cf. A055494, A246392, A250174, A250178, A250181, A250185, A250187, A250193, A260558-A260573.

Programs

  • Magma
    [n: n in [1..10000] |IsPrime((n^71 + 1) div (n + 1))]
  • Mathematica
    Select[Range[1, 10000], PrimeQ[(#^71 + 1)/(# + 1)] &]
  • PARI
    for(n=1,10000, if(isprime((n^71+1)/(n+1)), print1(n,", ")))

A260569 Numbers n such that (n^73+1)/(n+1) is prime.

Original entry on oeis.org

18, 214, 280, 394, 422, 444, 447, 571, 745, 787, 796, 886, 954, 960, 987, 1012, 1055, 1140, 1194, 1212, 1224, 1227, 1349, 1583, 1598, 1640, 1686, 1714, 1723, 1750, 1931, 1962, 2032, 2036, 2110, 2223, 2339, 2774, 2827, 2859, 2957, 3063, 3192, 3236, 3285, 3485
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Jul 29 2015

Keywords

Links

Crossrefs

Cf. A055494, A246392, A250174, A250178, A250181, A250185, A250187, A250193, A260558-A260573.

Programs

  • Magma
    [n: n in [1..10000] |IsPrime((n^73 + 1) div (n + 1))]
  • Mathematica
    Select[Range[1, 10000], PrimeQ[(#^73 + 1)/(# + 1)] &]
  • PARI
    for(n=1,10000, if(isprime((n^73+1)/(n+1)), print1(n,", ")))

A260570 Numbers n such that (n^79+1)/(n+1) is prime.

Original entry on oeis.org

2, 20, 22, 35, 47, 72, 109, 133, 184, 211, 226, 259, 352, 470, 559, 720, 785, 800, 823, 842, 895, 1003, 1145, 1172, 1213, 1291, 1318, 1375, 1441, 1453, 1460, 1461, 1467, 1477, 1604, 1608, 1637, 1654, 1695, 1703, 1807, 1831, 1834, 1903, 1948, 2035, 2060, 2065
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Jul 29 2015

Keywords

Links

Crossrefs

Cf. A055494, A246392, A250174, A250178, A250181, A250185, A250187, A250193, A260558-A260573.

Programs

  • Magma
    [n: n in [1..10000] |IsPrime((n^79 + 1) div (n + 1))]
  • Mathematica
    Select[Range[1, 10000], PrimeQ[(#^79 + 1)/(# + 1)] &]
  • PARI
    for(n=1,10000, if(isprime((n^79+1)/(n+1)), print1(n,", ")))

A291689 Numbers n such that n^2 +- n +- 1 are all composite.

Original entry on oeis.org

23, 37, 43, 52, 73, 74, 82, 88, 92, 98, 107, 108, 109, 113, 122, 123, 124, 128, 129, 133, 136, 137, 152, 157, 166, 178, 179, 183, 198, 201, 202, 205, 208, 211, 212, 213, 214, 217, 222, 223, 224, 227, 228, 229, 235, 238, 239, 243, 250, 251, 252, 253, 254, 255, 256, 257, 261, 262, 270, 271, 274
Offset: 1

Views

Author

Robert Israel, Aug 29 2017

Keywords

Comments

Numbers n such that A291654(n)=1.
Complement of union of A002328, A002384, A045546 and A055494.

Examples

			a(1)=23 is in the sequence because 23^2 - 23 - 1 = 505, 23^2 - 23 + 1 = 507, 23^2 + 23 - 1 = 551, 23^2 + 23 + 1 = 553 are all composite.

Links

Crossrefs

Cf. A002328, A002384, A045546, A055494, A291654.

Programs

  • Maple
    select(t -> not ormap(isprime, {t^2+t+1,t^2+t-1,t^2-t+1,t^2-t-1}), [$1..1000]);
  • Mathematica
    Select[Range@ 300, Function[t, AllTrue[t^2 + Map[Total[{t, 1} #] &, Tuples[{1, -1}, 2]], ! PrimeQ@ # &]]] (* Michael De Vlieger, Aug 29 2017 *)
  • PARI
    is(n)=my(n2=n^2); !isprime(n2+n+1) && !isprime(n2+n-1) && !isprime(n2-n+1) && !isprime(n2-n-1) \\ Charles R Greathouse IV, Aug 30 2017

Formula

a(n) ~ n. - Charles R Greathouse IV, Aug 30 2017
Previous Showing 31-38 of 38 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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