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 47 results. Next

A115244 Indices of primes generated by Fung and Ruby's prime generating polynomial A050268.

Original entry on oeis.org

402, 299, 206, 118, 24, 78, 141, 191, 224, 257, 272, 279, 276, 264, 242, 211, 167, 112, 38, 72, 162, 256, 350, 448, 558, 670, 786, 913, 1042, 1181, 1319, 1462, 1620, 1777, 1942, 2119, 2289, 2473, 2664, 2851, 3051, 3250, 3458, 3684
Offset: 0

Views

Author

Roger L. Bagula, May 11 2006

Keywords

Comments

PrimePi[Negative Prime]=0 :Absolute value is necessary because of this.

Crossrefs

Programs

  • Maple
    map(numtheory:-pi,select(isprime, [seq(abs(36*n^2 - 810* n + 2753), n=0..300)])); # Robert Israel, Mar 03 2016
  • Mathematica
    Table[PrimePi[Abs[36*n^2 - 810*n + 2753]], {n, 0, 43}]
    a := Select[Table[36 n^2 - 810 n + 2753, {n, 0, 200}], PrimeQ];
    PrimePi[Abs[a]] (* G. C. Greubel, Feb 08 2016 *)

Formula

a(n) = PrimePi(Abs(A050268(n))).

Extensions

Name edited by Robert Israel, Mar 03 2016

A050267 Primes or negative values of primes in the sequence b(n) = 47*n^2 - 1701*n + 10181, n >= 0.

Original entry on oeis.org

10181, 8527, 6967, 5501, 4129, 2851, 1667, 577, -419, -1321, -2129, -2843, -3463, -3989, -4421, -4759, -5003, -5153, -5209, -5171, -5039, -4813, -4493, -4079, -3571, -2969, -2273, -1483, -599, 379, 1451, 2617, 3877, 5231, 6679, 8221, 9857, 11587, 13411, 15329, 17341, 19447, 21647, 31387
Offset: 1

Views

Author

Keywords

Comments

Terms are listed in the order of their appearance in sequence b.
This is a transformed version of the polynomial P(x) = 47*x^2 + 9*x - 5209 whose absolute value gives 43 distinct primes for -24 <= x <= 18, found by G. W. Fung in 1988. - Hugo Pfoertner, Dec 13 2019

References

  • R. K. Guy, Unsolved Problems in Number Theory, 3rd ed., Springer, 2004 (ISBN 0-387-20860-7); see Section A17, p. 59.
  • Paulo Ribenboim, The Little Book of Bigger Primes, Second Edition, Springer-Verlag New York, 2004. See p. 147.

Crossrefs

Programs

Extensions

Edited by N. J. A. Sloane, May 10 2007
Further edited by Klaus Brockhaus, Mar 20 2010
More terms (to distinguish from quadratic) from Charles R Greathouse IV, Jun 18 2017

A271980 Numbers k such that 3*k^2 + 39*k + 37 is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 25, 26, 29, 30, 31, 32, 33, 34, 35, 38, 39, 40, 41, 42, 44, 45, 46, 48, 49, 51, 52, 53, 54, 55, 57, 58, 59, 60, 63, 64, 66, 68, 69, 70, 71, 72, 79, 84, 86, 88, 89, 90, 91, 92
Offset: 1

Views

Author

Robert Price, Apr 17 2016

Keywords

Comments

From Peter Bala, Apr 16 2018: (Start)
Let P(n) = 3*n^2 + 39*n + 37. The absolute values of the polynomial P(2*n - 29) = 12*n^2 - 270*n + 1429 for n from 0 to 27 are distinct primes, except at n = 14 when the value is 1.
The absolute values of the polynomial 3*P((n - 20)/3) = n^2 - n - 269 for n from 0 to 42 are either prime or 3 times a prime.
The absolute values of the polynomial 3*P((4*n - 89)/3) = 16*n^2 - 556*n + 4561 for n from 0 to 27 are either prime or 3 times a prime. (End)

Examples

			4 is in this sequence since 3*4^2 + 39*4 + 37 = 48+156+37 = 241 is prime.
		

Crossrefs

Programs

  • Magma
    [n: n in [0..100] |IsPrime(3*n^2+39*n+37)]; // Vincenzo Librandi, Apr 19 2018
  • Mathematica
    Select[Range[0, 100], PrimeQ[3*#^2 + 39*# + 37] &]
  • PARI
    isok(n) = isprime(3*n^2 + 39*n + 37); \\ Michel Marcus, Apr 17 2016
    
  • PARI
    lista(nn) = for(n=0, nn, if(ispseudoprime(3*n^2+39*n+37), print1(n, ", "))); \\ Altug Alkan, Apr 18 2016
    

A272074 Numbers k such that k^4 + 29*k^2 + 101 is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 23, 26, 31, 32, 34, 35, 37, 43, 44, 45, 47, 49, 53, 56, 60, 61, 62, 66, 67, 68, 70, 71, 72, 74, 75, 79, 80, 81, 84, 85, 89, 90, 91, 93, 96, 99
Offset: 1

Views

Author

Robert Price, Apr 19 2016

Keywords

Examples

			4 is in this sequence since 4^4 + 29*4^2 + 101 = 256+464+101 = 821 is prime.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[0,100],PrimeQ[#^4+29#^2+101]&] (* Harvey P. Dale, Dec 15 2020 *)
  • PARI
    lista(nn) = for(n=0, nn, if(ispseudoprime(n^4+29*n^2+101), print1(n, ", "))); \\ Altug Alkan, Apr 19 2016

A272075 Primes of the form k^4 + 29*k^2 + 101.

Original entry on oeis.org

101, 131, 233, 443, 821, 1451, 2441, 3923, 6053, 9011, 13001, 18251, 25013, 33563, 44201, 57251, 73061, 92003, 114473, 140891, 207371, 295283, 476681, 951491, 1078373, 1369961, 1536251, 1913963, 3472523, 3804341, 4159451, 4943843, 5834531, 7972043, 9925541
Offset: 1

Views

Author

Robert Price, Apr 19 2016

Keywords

Examples

			233 is prime and it is in this sequence since 233 = 2^4 + 29*2^2 + 101.
		

Crossrefs

Programs

  • Mathematica
    n = Range[0, 100]; Select[#^4 + 29#^2 + 101, PrimeQ[#] &]
  • PARI
    lista(nn) = for(n=0, nn, if(ispseudoprime(p=n^4+29*n^2+101), print1(p, ", "))); \\ Altug Alkan, Apr 19 2016

A272160 Primes of the form abs(8n^2 - 488n + 7243) in order of increasing nonnegative values of n.

Original entry on oeis.org

7243, 6763, 6299, 5851, 5419, 5003, 4603, 4219, 3851, 3499, 3163, 2843, 2539, 2251, 1979, 1723, 1483, 1259, 1051, 859, 683, 523, 379, 251, 139, 43, 37, 101, 149, 181, 197, 197, 181, 149, 101, 37, 43, 139, 251, 379, 523, 683, 859, 1051, 1259, 1483, 1723, 1979
Offset: 1

Views

Author

Robert Price, Apr 21 2016

Keywords

Examples

			5419 is in this sequence since 8*4^2 - 488*4 + 7243 = 128-1952+7243 = 5419 is prime.
		

Crossrefs

Programs

  • Mathematica
    n = Range[0, 100]; Select[Abs[8n^2 - 488n + 7243], PrimeQ[#] &]
  • PARI
    lista(nn) = for(n=0, nn, if(isprime(p=abs(8*n^2-488*n+7243)), print1(p, ", "))); \\ Altug Alkan, Apr 21 2016

A271144 Primes of the form 42*k^3 + 270*k^2 - 26436*k + 250703 in order of increasing k.

Original entry on oeis.org

250703, 224579, 199247, 174959, 151967, 130523, 110879, 93287, 77999, 65267, 55343, 48479, 44927, 44939, 48767, 56663, 68879, 85667, 107279, 133967, 165983, 203579, 247007, 296519, 352367, 414803, 484079, 560447, 644159, 735467, 834623, 941879, 1057487
Offset: 1

Views

Author

Robert Price, Apr 23 2016

Keywords

Examples

			151967 is prime and it is in this sequence since 151967 = 42*4^3 + 270*4^2 - 26436*4 + 250703.
		

Crossrefs

Programs

  • Mathematica
    n = Range[0, 100]; Select[42n^3 + 270n^2 - 26436n + 250703, PrimeQ[#] &]

A272159 Numbers k such that abs(8*k^2 - 488*k + 7243) is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 65, 66, 67, 71
Offset: 1

Views

Author

Robert Price, Apr 21 2016

Keywords

Comments

From Robert Israel, Apr 21 2016: (Start)
n such that either n <= 61 or 8n^2 - 488n + 7243 is prime.
The first number not in the sequence is 62. (End)

Examples

			4 is in this sequence since 8*4^2 - 488*4 + 7243 = 128-1952+7243 = 5419 is prime.
		

Crossrefs

Programs

  • Maple
    select(n -> isprime(abs(8*n^2 - 488*n + 7243)), [$0..1000]); # Robert Israel, Apr 21 2016
  • Mathematica
    Select[Range[0, 100], PrimeQ[8#^2 - 488# + 7243] &]
  • PARI
    lista(nn) = for(n=0, nn, if(isprime(abs(8*n^2-488*n+7243)), print1(n, ", "))); \\ Altug Alkan, Apr 21 2016

A271143 Numbers k such that 42*k^3 + 270*k^2 - 26436*k + 250703 is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 41, 43, 44, 48, 51, 54, 55, 56, 58, 61, 62, 63, 64, 65, 66, 67, 69, 71, 76, 78, 79, 84, 87, 88, 89, 90, 92
Offset: 1

Views

Author

Robert Price, Apr 23 2016

Keywords

Comments

40 is the first value not in the sequence.

Examples

			4 is in this sequence since 42*4^3 + 270*4^2 - 26436*4 + 250703 = 151967, which is prime.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 100], PrimeQ[42#^3 + 270#^2 - 26436# + 250703] &]
  • PARI
    is(n)=isprime(42*n^3+270*n^2-26436*n+250703) \\ Charles R Greathouse IV, Feb 17 2017

A272285 Primes of the form 43*n^2 - 537*n + 2971 in order of increasing nonnegative values of n.

Original entry on oeis.org

2971, 2477, 2069, 1747, 1511, 1361, 1297, 1319, 1427, 1621, 1901, 2267, 2719, 3257, 3881, 4591, 5387, 6269, 7237, 8291, 9431, 10657, 11969, 13367, 14851, 16421, 18077, 19819, 21647, 23561, 25561, 27647, 29819, 32077, 34421, 39367, 41969, 44657, 47431, 50291
Offset: 1

Views

Author

Robert Price, Apr 24 2016

Keywords

Examples

			1511 is in this sequence since 43*4^2 - 537*4 + 2971 = 688-2148+2971 = 1511 is prime.
		

Crossrefs

Programs

  • Mathematica
    n = Range[0, 100]; Select[43n^2 - 537n + 2971, PrimeQ[#] &]
  • PARI
    lista(nn) = for(n=0, nn, if(ispseudoprime(p=43*n^2 - 537*n + 2971), print1(p, ", "))); \\ Altug Alkan, Apr 24 2016
Showing 1-10 of 47 results. Next