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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A272325 Nonnegative numbers n such that n^4 + 853n^3 + 2636n^2 + 3536n + 1753 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, 22, 25, 26, 27, 30, 34, 37, 41, 43, 46, 50, 52, 53, 56, 59, 60, 61, 64, 66, 67, 68, 71, 76, 79, 81, 84, 87, 88, 89, 91, 92, 95, 96, 98, 99, 103, 106, 109, 118, 124, 126, 127, 128, 132
Offset: 1

Views

Author

Robert Price, Apr 25 2016

Keywords

Comments

21 is the smallest number not in this sequence.

Examples

			4 is in this sequence since 4^4 + 853*4^3 + 2636*4^2 + 3536*4 + 1753 = 256+54592+42176+14144+1753 = 112921 is prime.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 100], PrimeQ[#^4 + 853#^3 + 2636#^2 + 3536# + 1753] &]
  • PARI
    lista(nn) = for(n=0, nn, if(isprime(n^4+853*n^3+2636*n^2+3536*n+1753), print1(n, ", "))); \\ Altug Alkan, Apr 25 2016

A272326 Primes of the form k^4 + 853*k^3 + 2636*k^2 + 3536*k + 1753 in order of increasing nonnegative k.

Original entry on oeis.org

1753, 8779, 26209, 59197, 112921, 192583, 303409, 450649, 639577, 875491, 1163713, 1509589, 1918489, 2395807, 2946961, 3577393, 4292569, 5097979, 5999137, 7001581, 8110873, 10672369, 15456403, 17324929, 19339909, 26321233, 38031841, 48822439, 66193219
Offset: 1

Views

Author

Robert Price, Apr 25 2016

Keywords

Examples

			112921 is in this sequence since 4^4 + 853*4^3 + 2636*4^2 + 3536*4 + 1753 = 256+54592+42176+14144+1753 = 112921 is prime.
		

Crossrefs

Programs

  • Mathematica
    n = Range[0, 100]; Select[n^4 + 853n^3 + 2636n^2 + 3536n + 1753, PrimeQ[#] &]
  • PARI
    lista(nn) = for(n=0, nn, if(isprime(p=n^4+853*n^3+2636*n^2+3536*n+1753), print1(p, ", "))); \\ Altug Alkan, Apr 25 2016

A272554 Nonnegative numbers n such that abs(1/(36)(n^6 - 126n^5 + 6217n^4 - 153066n^3 + 1987786n^2 - 13055316n + 34747236)) 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, 57, 61, 62, 63, 64, 65, 66, 68, 69, 70, 73, 78
Offset: 1

Views

Author

Robert Price, May 02 2016

Keywords

Comments

55 is the smallest number not in this sequence.

Examples

			4 is in this sequence since abs(1/(36)(4^6 - 126*4^5 + 6217*4^4 - 153066*4^3 + 1987786*4^2 - 13055316*4 + 34747236)) = abs((4096 - 129024 + 1591552 - 9796224 + 31804576 - 5222126 + 34747236)/36) = 166693 is prime.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 100], PrimeQ[1/(36)(#^6 - 126#^5 + 6217#^4 - 153066#^3 + 1987786#^2 - 13055316# + 34747236)] &]

A272710 Primes of the form abs((1/4)*(n^5 - 133n^4 + 6729n^3 - 158379n^2 + 1720294n - 6823316)) in order of increasing nonnegative n.

Original entry on oeis.org

1705829, 1313701, 991127, 729173, 519643, 355049, 228581, 134077, 65993, 19373, 10181, 26539, 33073, 32687, 27847, 20611, 12659, 5323, 383, 3733, 4259, 1721, 3923, 12547, 23887, 37571, 53149, 70123, 87977, 106207, 124351, 142019, 158923, 174907, 189977
Offset: 1

Views

Author

Robert Price, May 04 2016

Keywords

Examples

			519643 is in this sequence since abs(1/4 (n^5 - 133n^4 + 6729n^3 - 158379n^2 + 1720294n - 6823316)) = abs((1024 - 34048 + 430656 - 2534064 + 6881176 - 6823316)/4) = 519643 is prime.
		

Crossrefs

Programs

  • Mathematica
    n = Range[0, 100]; Select[1/4 (n^5 - 133n^4 + 6729n^3 - 158379n^2 + 1720294n - 6823316), PrimeQ[#] &]

A105551 Number of distinct prime factors of n^3 + n^2 + 71.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 3, 2, 2, 2, 2, 1, 3, 3, 2, 1, 2, 1, 1, 3, 2, 3, 1, 2, 1, 1, 3, 2, 1, 2, 3, 2, 2, 2, 1, 3, 1, 1, 3, 2, 1, 2
Offset: 0

Views

Author

Jonathan Vos Post, May 03 2005

Keywords

Comments

This cubic equation with small positive coefficients is strangely rich in primes and semiprimes. The first 44 consecutive values, for n = 0, 1, 2, ..., 43, are all either prime (23 of them) or semiprime (21 of them), before the first 3-almost prime value is encountered.

Examples

			a(0) = 1 because 0^3 + 0^2 + 71 = 71 is prime.
a(1) = 1 because 1^3 + 1^2 + 71 = 73 is prime.
a(2) = 1 because 2^3 + 2^2 + 71 = 83 is prime.
a(3) = 1 because 3^3 + 3^2 + 71 = 107 is prime.
a(4) = 1 because 3^3 + 3^2 + 71 = 151 is prime.
a(5) = 2 because 3^3 + 3^2 + 71 = 221 = 13 * 17 is the first semiprime.
a(44) = 3 because 44^3 + 44^2 + 71 = 87191 = 13 * 19 * 353 is the first 3-almost prime for nonnegative integers n.
		

Crossrefs

Programs

Formula

a(n) = A001221(n^3 + n^2 + 71).

Extensions

More terms from Robert G. Wilson v, May 21 2005

A128878 Primes of the form 47*n^2 - 1701*n + 10181.

Original entry on oeis.org

10181, 8527, 6967, 5501, 4129, 2851, 1667, 577, 379, 1451, 2617, 3877, 5231, 6679, 8221, 9857, 11587, 13411, 15329, 17341, 19447, 21647, 31387, 34057, 36821, 39679, 45677, 48817, 52051, 65927, 81307, 89561, 102647, 107197, 116579, 126337, 131357
Offset: 1

Views

Author

Douglas Winston (douglas.winston(AT)srupc.com), Apr 17 2007

Keywords

Comments

Primes are given in the order in which they arise for increasing n.
Polynomial generates 22 primes for 0 <= n <= 42, i.e., for n = 0, 1, 2, 3, 4, 5, 6, 7, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42.
If the definition is replaced by "Numbers n of the form 47*k^2 - 1701*k + 10181 such that either n or -n is a prime" we get (essentially) A050267.

Examples

			47k^2 - 1701k + 10181 = 21647 for k = 42.
		

References

  • R. K. Guy, Unsolved Problems in Number Theory, 3rd edition, Springer, 2004, ISBN 0-387-20860-7, Section A17, page 59.

Crossrefs

Programs

  • Mathematica
    Select[Table[47*n^2 - 1701*n + 10181, {n, 0, 100}], # > 0 && PrimeQ[#] &] (* T. D. Noe, Aug 02 2011 *)

Extensions

Edited by Klaus Brockhaus, Apr 22 2007 and by N. J. A. Sloane, May 05 2007 and May 06 2007

A212325 Prime-generating polynomial: a(n) = n^2 + 3*n - 167.

Original entry on oeis.org

-167, -163, -157, -149, -139, -127, -113, -97, -79, -59, -37, -13, 13, 41, 71, 103, 137, 173, 211, 251, 293, 337, 383, 431, 481, 533, 587, 643, 701, 761, 823, 887, 953, 1021, 1091, 1163, 1237, 1313, 1391, 1471, 1553, 1637, 1723, 1811, 1901, 1993, 2087, 2183, 2281, 2381
Offset: 0

Views

Author

Marius Coman, May 14 2012

Keywords

Comments

The polynomial generates 24 primes in absolute value (23 distinct ones) in row starting from n=0 (and 42 primes in absolute value for n from 0 to 46).
The polynomial n^2 - 49*n + 431 generates the same primes in reverse order.
Note: we found in the same family of prime-generating polynomials (with the discriminant equal to 677) the polynomial 13*n^2 - 311*n + 1847 (13*n^2 - 469*n + 4217) generating 23 primes and two noncomposite numbers (in absolute value) in row starting from n=0 (1847, 1549, 1277, 1031, 811, 617, 449, 307, 191, 101, 37, -1, -13, 1, 41, 107, 199, 317, 461, 631, 827, 1049, 1297, 1571, 1871).
Note: another interesting algorithm to produce prime-generating polynomials could be N = m*n^2 + (6*m+1)*n + 8*m + 3, where m, 6*m+1 and 8*m+3 are primes. For m=7 then n=t-20 we get N = 7*t^2 - 237*t + 1999, which generates the following primes: 239, 163, 101, 53, 19, -1, -7, 1, 23, 59, 109, 173, 251 (we can see the same pattern: …, -1, -m, 1, …).

Crossrefs

Cf. A060566 (an 80 primes generating pol.), A202018 (Euler's p.g.p.), A050268, A181963, A181973, A182409, A211773, A318791, A320772, A330363 (other p.g.p.).

Programs

  • Magma
    [n^2+3*n-167: n in [0..47]]; // Bruno Berselli, May 18 2012
    
  • Mathematica
    Table[n^2+3n-167,{n,0,50}] (* or *) LinearRecurrence[{3,-3,1},{-167,-163,-157},50] (* Harvey P. Dale, Feb 08 2020 *)
  • PARI
    Vec((-167+338*x-169*x^2)/(1-x)^3+O(x^99)) \\ Charles R Greathouse IV, Oct 01 2012
    
  • PARI
    apply( {A212325(n)=(n+3)*n-167}, [0..55]) \\ M. F. Hasler, Feb 11 2025
    
  • Python
    def A212325(n=None, upto=None): return(A212325(i)for i in range(n or 0, upto or 2**63)) if upto or n is None else(n+3)*n-167 # M. F. Hasler, Feb 11 2025

Formula

G.f.: (-167 + 338*x - 169x^2)/(1-x)^3. - Bruno Berselli, May 18 2012
From Elmo R. Oliveira, Feb 10 2025: (Start)
E.g.f.: exp(x)*(-167 + 4*x + x^2).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 2. (End)

Extensions

Edited by Bruno Berselli, May 18 2012

A247163 Nonnegative numbers n such that abs(1/4 (n^5 - 133n^4 + 6729n^3 - 158379n^2 + 1720294n - 6823316)) 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, 59, 60, 61, 64, 67, 68, 69, 74, 75, 76
Offset: 1

Views

Author

Robert Price, May 04 2016

Keywords

Comments

62 is the smallest number not in this sequence.

Examples

			4 is in this sequence since abs(1/4 (n^5 - 133n^4 + 6729n^3 - 158379n^2 + 1720294n - 6823316)) = abs((1024 - 34048 + 430656 - 2534064 + 6881176 - 6823316)/4) = 519643 is prime.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 100], PrimeQ[1/4 (#^5 - 133#^4 + 6729#^3 - 158379#^2 + 1720294# - 6823316)] &]

A267069 Nonnegative numbers n such that abs(103*n^2 - 4707*n + 50383) 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, 44, 45, 47, 49, 50, 51, 52, 53, 54, 57, 59, 60, 61, 63, 64, 65, 66, 67, 69, 73, 74, 76, 77, 80
Offset: 1

Views

Author

Robert Price, Apr 28 2016

Keywords

Comments

43 is the smallest number not in this sequence.
See A267252 for more information. - Hugo Pfoertner, Dec 13 2019

Examples

			4 is in this sequence since 103*4^2 - 4707*4 + 50383  = 1648-18828+50383 = 33203 is prime.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 100], PrimeQ[103#^2 - 4707# + 50383 ] &]
  • PARI
    lista(nn) = for(n=0, nn, if(isprime(abs(103*n^2-4707*n+50383)), print1(n, ", "))); \\ Altug Alkan, Apr 28 2016, corrected by Hugo Pfoertner, Dec 13 2019

Extensions

Title corrected by Hugo Pfoertner, Dec 13 2019

A272076 Numbers n such that abs(7*n^2 - 371*n + 4871) 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, 25, 26, 27, 28, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 55, 56, 59, 61, 63, 65, 67, 68, 72, 73, 74, 75, 76, 77, 78
Offset: 1

Views

Author

Robert Price, Apr 19 2016

Keywords

Examples

			4 is in this sequence since 7*4^2 - 371*4 + 4871 = 112-1484+4871 = 3499 is prime.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 100], PrimeQ[7#^2 - 371# + 4871] &]
  • PARI
    lista(nn) = for(n=0, nn, if(ispseudoprime(abs(7*n^2-371*n+4871)), print1(n, ", "))); \\ Altug Alkan, Apr 19 2016
Previous Showing 31-40 of 47 results. Next