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 1-4 of 4 results.

A127484 Numbers k such that A127483(k) = A127483(k+1) - 1.

Original entry on oeis.org

1, 2, 3, 8, 13, 14, 22, 23, 24, 34, 38, 64, 98, 99, 133, 147, 153, 178, 232, 253, 254, 297, 328, 343, 344, 367, 407, 498, 573, 574, 582, 587, 624, 638, 639, 653, 668, 679, 702, 703, 759, 772, 793, 797, 849, 874, 944, 958, 1023, 1058, 1067, 1087, 1203, 1212, 1322
Offset: 1

Views

Author

Alexander Adamchuk, Jan 16 2007

Keywords

Comments

A127483(n) = {1,2,3,4,8,9,13,14,15,17,22,23,24,25,30,32,34,35,38,39,42,45,50,...} are the numbers n such that A100705(n) = n^3 + (n+1)^2 is prime.
Corresponding primes of the form n^3 + (n+1)^2 are listed in A100662(n) = {5, 17, 43, 89, 593, 829, 2393, 2969, 3631, 5237, ...}.
Note that there are many consecutive twins, triples and quadruplets in A127483(n). For example: (1,2,3,4), {8,9}, {13,14,15}, {22,23,24,25}, {34,35}, {38,39}, {64,65}, {98,99,100}. Twins in A127483(k) start with numbers k = a(n). Triplets in A127483(k) start with k = {1,2,13,22,23,98,253,343,573,638,702,...} = A127485, or numbers n such that a(k) = a(k+1) - 1 = a(k+2) - 2. Quadruplets in A127483(k) start with k = {1,22,13077,14267,16092,16267,16282,36387,47012,51912,54662,...} = A127486.

Crossrefs

Programs

  • Magma
    [k:k in [1..1350]|IsPrime(k^3+(k+1)^2) and IsPrime((k+1)^3+(k+2)^2)]; // Marius A. Burtea, Jan 20 2020
  • Mathematica
    Select[Range[3000],PrimeQ[ #^3+(#+1)^2]&&PrimeQ[(#+1)^3+(#+2)^2]&]

A127485 Numbers k such that A127483(k) = A127483(k+1) - 1 = A127483(k+2) - 2.

Original entry on oeis.org

1, 2, 13, 22, 23, 98, 253, 343, 573, 638, 702, 1322, 1862, 2543, 2638, 2758, 2792, 2912, 3093, 3158, 3242, 3578, 3968, 4382, 5013, 6503, 7048, 7877, 8372, 8912, 9022, 9207, 10298, 10443, 11538, 12482, 13077, 13078, 13868, 14267, 14268, 14323, 14783
Offset: 1

Views

Author

Alexander Adamchuk, Jan 16 2007

Keywords

Comments

A127483(n) = {1,2,3,4,8,9,13,14,15,17,22,23,24,25,30,32,34,35,38,39,42,45,50,...} are the numbers n such that A100705(n) = n^3 + (n+1)^2 is prime. Corresponding primes of the form n^3 + (n+1)^2 are listed in A100662(n) = {5, 17, 43, 89, 593, 829, 2393, 2969, 3631, 5237, ...}. Note that there are many consecutive twins, triples and quadruplets in A127483(n). For example: (1,2,3,4), {8,9}, {13,14,15}, {22,23,24,25}, {34,35}, {38,39}, {64,65}, {98,99,100}. Twins in A127483(k) start with k = {1,2,3,8,13,14,22,23,24,34,38,64,98,99,133,147,153,178,232,253,254,297,328,343, 344,367,407,498,...} = A127484. Triplets in A127483(k) start with numbers k = a(n). Quadruplets in A127483(k) start with k = {1,22,13077,14267,16092,16267,16282,36387,47012,51912,54662,...} = A127486.

Crossrefs

Programs

  • Magma
    f:=func; [k:k in [1..15000]|f(k) and f(k+1) and f(k+2)]; // Marius A. Burtea, Jan 20 2020
  • Mathematica
    Select[Range[30000],PrimeQ[ #^3+(#+1)^2]&&PrimeQ[(#+1)^3+(#+2)^2]&&PrimeQ[(#+2)^3+(#+3)^2]&]

A127486 Numbers k such that A127483(k) = A127483(k+1) - 1 = A127483(k+2) - 2 = A127483(k+3) - 3.

Original entry on oeis.org

1, 22, 13077, 14267, 16092, 16267, 16282, 36387, 47012, 51912, 54662, 144487, 181777, 205897, 210022, 213982, 250517, 263717, 344092, 409697, 454607, 568777, 643677, 665917, 702947, 749967, 824167, 858187, 887677, 888427, 997787, 1075537
Offset: 1

Views

Author

Alexander Adamchuk, Jan 16 2007

Keywords

Comments

A127483(n) = {1,2,3,4,8,9,13,14,15,17,22,23,24,25,30,32,34,35,38,39,42,45,50,...} are the numbers n such that A100705(n) = n^3 + (n+1)^2 is prime. Corresponding primes of the form n^3 + (n+1)^2 are listed in A100662(n) = {5, 17, 43, 89, 593, 829, 2393, 2969, 3631, 5237, ...}. Note that there are many consecutive twins, triples and quadruplets in A127483(n). For example: (1,2,3,4), {8,9}, {13,14,15}, {22,23,24,25}, {34,35}, {38,39}, {64,65}, {98,99,100}. Twins in A127483(k) start with k = {1,2,3,8,13,14,22,23,24,34,38,64,98,99,133,147,153,178,232,253,254,297,328,343, 344,367,407,498,...} = A127484. Triplets in A127483(k) start with k = {1,2,13,22,23,98,253,343,573,638,702,...} = A127485. Quadruplets in A127483(k) start with numbers k = a(n).
For n>1 the final digit of all listed terms of a(n) is 2 or 7. - Alexander Adamchuk, Jan 16 2007

Crossrefs

Programs

  • Mathematica
    f[s_]:=s^3+(s+1)^2; Do[If[PrimeQ[f[n]]&&PrimeQ[f[n+1]]&&PrimeQ[f[n+2]]&&PrimeQ[f[n+3]],Print[n]],{n,1,100000}]

Extensions

More terms from Alexander Adamchuk, Jan 16 2007

A100662 Primes of the form k^3 + (k+1)^2.

Original entry on oeis.org

5, 17, 43, 89, 593, 829, 2393, 2969, 3631, 5237, 11177, 12743, 14449, 16301, 27961, 33857, 40529, 44171, 56393, 60919, 75937, 93241, 127601, 198593, 219721, 266369, 278981, 499439, 578843, 621521, 689393, 737281, 787337, 839609, 950993, 980299, 1010201, 1071817
Offset: 1

Views

Author

Giovanni Teofilatto, Jan 03 2005

Keywords

Examples

			a(1) = 5 because 5 = 1^3 + 2^2.
a(2) = 17 because 17 = 2^3 + 3^2.
a(3) = 43 because 43 = 3^3 + 4^2.
		

Crossrefs

Intersection of A100705 and A000040.
Cf. A127483.

Programs

  • Magma
    [ a: n in [0..100] | IsPrime(a) where a is n^3 + (n+1)^2 ]; // Vincenzo Librandi, Jul 18 2012
    
  • Mathematica
    Select[Table[n^3+(n+1)^2,{n,200}],PrimeQ] (* Vladimir Joseph Stephan Orlovsky, Feb 01 2012 *)
  • PARI
    list(lim)=my(v=List(),t); for(n=1,lim, t=n^3+(n+1)^2; if(t>lim, break); if(isprime(t), listput(v,t))); Vec(v) \\ Charles R Greathouse IV, Dec 23 2016

Formula

a(n) = A100705(A127483(n)). - Elmo R. Oliveira, Apr 19 2025

Extensions

More terms from Mark Hudson, Jan 04 2005
Showing 1-4 of 4 results.