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 10 results.

A187060 Primes p such that the polynomial x^2 + x + p generates only primes for x = 1..7.

Original entry on oeis.org

11, 17, 41, 21557, 26681, 128981, 844427, 2073347, 3992201, 4889237, 6184637, 11900501, 21456047, 24598361, 33771581, 34864211, 50943791, 51448361, 51867197, 55793951, 56421347, 61218251, 67787537, 69726647, 76345121
Offset: 1

Views

Author

Jonathan Vos Post, Mar 03 2011

Keywords

Comments

From Weber, p. 15. However, erroneous.
All terms = {11,17} mod 30. - Zak Seidov, May 08 2011

Examples

			a(4) <> 21577 because 0^2 + 0 + 21577 = 21577; 1^2 + 1 + 21577 = 21579 = 3 * 7193 thus exposing an error in Weber's paper; 2^2 + 2 + 21577 = 21583 = 113 * 191; 3^2 + 3 + 21577 = 21589 is prime; 4^2 + 4 + 21577 = 21597 = 3 * 23 * 313; 5^2 + 5 + 21577 = 21607 = 17 * 31 * 41 (a "3-brilliant number" rather than a prime); 6^2 + 6 + 21577 = 21619 = 13 * 1663; 7^2 + 7 + 21577 = 21633 = 3 * 7211.
		

Crossrefs

Programs

  • Mathematica
    okQ[n_] := And @@ PrimeQ[Table[i^2 + i + n, {i, 0, 7}]]; Select[Range[10000], okQ] (* T. D. Noe, Mar 03 2011 *)
  • PARI
    for(k=1,50000,p=prime(k); if(isprime(p+2) && isprime(p+6) && isprime(p+12) && isprime(p+20) && isprime(p+30) && isprime(p+42) && isprime(p+56),print(p),)) \\ Nathaniel Johnston, Apr 26 2011
    
  • PARI
    p=2;q=3;forprime(r=5,1e6,if(r-p==6 && q-p==2 && isprime(p+12) && isprime(p+20) && isprime(p+30) && isprime(p+42) && isprime(p+56),print(p));p=q;q=r) \\ Charles R Greathouse IV, Mar 04 2012

Extensions

a(12)-a(25) from Nathaniel Johnston, Apr 26 2011

A144051 Primes p such that the polynomial x^2 + x + p generates only primes for x = 1..6.

Original entry on oeis.org

11, 17, 41, 1277, 21557, 26681, 28277, 113147, 128981, 421697, 665111, 844427, 1164587, 1615631, 2073347, 2798921, 2846771, 3053747, 3992201, 4889237, 5071667, 5093507, 5344247, 5706641, 6184637, 6383051, 8396777
Offset: 1

Views

Author

Keywords

Comments

All terms = {11,17} mod 30. - Zak Seidov, May 08 2011

Examples

			a(3) = 41 because 0^2 + 0 + 41 = 41; 1^2 + 1 + 41 = 43; 2^2 + 2 + 41 = 47; 3^2 + 3 + 41 = 53; 4^2 + 4 + 41 = 61; 5^2 + 5 + 41 = 71; 6^2 + 6 + 41 = 83, all primes.
		

Crossrefs

Programs

  • Mathematica
    lst={}; Do[p1=Prime[n]; If[PrimeQ[p2=p1+2] && PrimeQ[p3=p1+6] && PrimeQ[p4=p1+12] && PrimeQ[p5=p1+20] && PrimeQ[p6=p1+30] && PrimeQ[p7=p1+42], AppendTo[lst,p1]], {n,10^5}]; lst
    okQ[n_] := And @@ PrimeQ[Table[i^2 + i + n, {i, 0, 6}]]; Select[Range[10000], okQ] (* T. D. Noe, Mar 03 2011 *)

A190817 Initial primes of 6 consecutive primes with consecutive gaps 2,4,6,8,10.

Original entry on oeis.org

13901, 21557, 28277, 55661, 68897, 128981, 221717, 354371, 548831, 665111, 954257, 1164587, 1246367, 1265081, 1538081, 1595051, 1634441, 2200811, 2798921, 2858621, 3053747, 3407081, 3414011, 3967487, 3992201, 4480241, 4608281, 4701731, 4809251, 5029457
Offset: 1

Views

Author

Zak Seidov, May 21 2011

Keywords

Comments

a(1) = 13901 = A190814(5) = A187058(7) = A078847(24).
a(n) + 30 is the greatest term in the sequence of 6 consecutive primes with consecutive gaps 2, 4, 6, 8, 10. - Muniru A Asiru, Aug 10 2017

Examples

			For n = 1, 13901 is in the sequence because 13901, 13903, 13907, 13913, 13921, 13931 are consecutive primes and for n = 2, 21557 is in the sequence since 21557, 21559, 21563, 21569, 21577, 21587 are consecutive primes. - _Muniru A Asiru_, Aug 24 2017
		

Crossrefs

Programs

  • GAP
    K:=3*10^7+1;; # to get all terms <= K.
    P:=Filtered([1,3..K],IsPrime);; I:=[2,4,6,8,10];;
    P1:=List([1..Length(P)-1],i->P[i+1]-P[i]);;
    P2:=List([1..Length(P)-Length(I)],i->[P1[i],P1[i+1],P1[i+2],P1[i+3],P1[i+4]]);;
    P3:=List(Positions(P2,I),i->P[i]);  # Muniru A Asiru, Aug 24 2017
  • Maple
    N:=10^7: # to get all terms <= N.
    Primes:=select(isprime,[seq(i,i=3..N+30,2)]):
    Primes[select(t->[Primes[t+1]-Primes[t], Primes[t+2]-Primes[t+1],Primes[t+3]-Primes[t+2], Primes[t+4]-Primes[t+3], Primes[t+5]-Primes[t+4]]=[2,4,6,8,10], [$1..nops(Primes)-5])]; # Muniru A Asiru, Aug 04 2017
  • Mathematica
    d = Differences[Prime[Range[100000]]]; Prime[Flatten[Position[Partition[d, 5, 1], {2, 4, 6, 8, 10}]]] (* T. D. Noe, May 23 2011 *)
    With[{s = Differences@ Prime@ Range[10^6]}, Prime[SequencePosition[s, Range[2, 10, 2]][[All, 1]] ] ] (* Michael De Vlieger, Aug 16 2017 *)
  • PARI
    lista(nn) = forprime(p=13901, nn, if(nextprime(p+1)==p+2 && nextprime(p+3)==p+6 && nextprime(p+7)==p+12 && nextprime(p+13)==p+20 && nextprime(p+21)==p+30, print1(p", "))); \\ Altug Alkan, Aug 16 2017
    

Extensions

Additional cross references from Harvey P. Dale, May 10 2014

A191456 Primes p such that the polynomial x^2+x+p generates only primes for x=1..9.

Original entry on oeis.org

11, 17, 41, 844427, 51448361, 86966771, 122983031, 180078317, 960959381, 1278189947, 1761702947, 1829187287, 2426256797, 2911675511, 3013107257, 4778888351, 5221343711
Offset: 1

Views

Author

Zak Seidov, Jun 02 2011

Keywords

Crossrefs

Generates primes for x=1..k: A001359 (1), A022004 (2), A172454 (3), A187057 (4), A187058 (5), A144051 (6), A187060 (7), A190800 (8), this sequence (9), A191457 (10), A191458 (11), A253592 (12), A253605 (13). Each is by definition a subsequence of preceding sequences.
Subsequence such that x=10 gives a composite number: A211238.

Programs

A247949 Primes p such that the polynomial k^4 + k^3 + k^2 + k + p yields only primes for k = 0...5.

Original entry on oeis.org

7, 43, 79, 457, 877, 967, 1093, 2437, 2683, 3187, 5077, 5923, 7933, 8233, 11923, 12889, 15787, 17389, 19993, 31543, 41113, 41617, 42457, 71359, 77863, 80683, 91393, 101719, 102643, 105967, 107347, 120163, 129733, 137593, 151783, 170263, 175723, 197569, 210127
Offset: 1

Views

Author

K. D. Bajpai, Jan 11 2015

Keywords

Comments

All terms == 1 mod 6. - Robert Israel, Jan 11 2015

Examples

			a(1) = 7:
0^4 + 0^3 + 0^2 + 0 + 7 = 7;
1^4 + 1^3 + 1^2 + 1 + 7 = 11;
2^4 + 2^3 + 2^2 + 2 + 7 = 37;
3^4 + 3^3 + 3^2 + 3 + 7 = 127;
4^4 + 4^3 + 4^2 + 4 + 7 = 347;
5^4 + 5^3 + 5^2 + 5 + 7 = 787;
all six are primes.
		

Crossrefs

Programs

  • Maple
    select(p -> andmap(isprime, [p, p+4, p+30, p+120, p+340, p+780]), [seq(6*i+1, i=1..10^5)]); # Robert Israel, Jan 11 2015
  • Mathematica
    Select[f=k^4 + k^3 + k^2 + k; k = {0, 1, 2, 3, 4, 5}; Prime[Range[2000000]], And @@ PrimeQ[#+f] &]
    Select[Prime[Range[20000]],AllTrue[#+{4,30,120,340,780},PrimeQ]&] (* Harvey P. Dale, Dec 24 2023 *)
  • PARI
    forprime(p=1, 500000, if( isprime(p+0)& isprime(p+4)& isprime(p+30)& isprime(p+120)& isprime(p+340)& isprime(p+780), print1(p,", ")))

A247966 Primes p such that the polynomial k^4 + k^3 + k^2 + k + p yields only primes for k = 0...6.

Original entry on oeis.org

43, 457, 967, 1093, 5923, 8233, 11923, 15787, 41113, 80683, 151783, 210127, 213943, 294919, 392737, 430879, 495559, 524827, 537007, 572629, 584557, 711727, 730633, 731593, 1097293, 1123879, 1138363, 1149163, 1396207, 1601503, 1739557, 1824139, 2198407, 2223853
Offset: 1

Views

Author

K. D. Bajpai, Jan 11 2015

Keywords

Examples

			a(1) = 43:
0^4 + 0^3 + 0^2 + 0 + 43 = 43;
1^4 + 1^3 + 1^2 + 1 + 43 = 47;
2^4 + 2^3 + 2^2 + 2 + 43 = 73;
3^4 + 3^3 + 3^2 + 3 + 43 = 163;
4^4 + 4^3 + 4^2 + 4 + 43 = 383;
5^4 + 5^3 + 5^2 + 5 + 43 = 823;
6^4 + 6^3 + 6^2 + 6 + 43 = 1597;
all seven are primes.
		

Crossrefs

Programs

  • Mathematica
    Select[f=k^4 + k^3 + k^2 + k; k = {0, 1, 2, 3, 4, 5, 6}; Prime[Range[2000000]], And @@ PrimeQ[#+f] &]
    Select[Prime[Range[200000]],AllTrue[#+{4,30,120,340,780,1554},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jan 10 2017 *)
  • PARI
    forprime(p=1, 1e6, if( isprime(p+0)& isprime(p+4)& isprime(p+30)& isprime(p+120)& isprime(p+340)& isprime(p+780)&  isprime(p+1554), print1(p,", ")))

A248206 Primes p such that the polynomial k^4 + k^3 + k^2 + k + p yields only primes for k = 0...7.

Original entry on oeis.org

43, 457, 967, 11923, 15787, 41113, 213943, 294919, 392737, 430879, 524827, 572629, 730633, 1097293, 1149163, 2349313, 2738779, 3316147, 3666007, 5248153, 5396617, 5477089, 7960009, 9949627, 10048117, 11260237, 11613289, 15281023, 16153279, 17250367, 18733807
Offset: 1

Views

Author

K. D. Bajpai, Jan 11 2015

Keywords

Examples

			a(1) = 43:
0^4 + 0^3 + 0^2 + 0 + 43 = 43;
1^4 + 1^3 + 1^2 + 1 + 43 = 47;
2^4 + 2^3 + 2^2 + 2 + 43 = 73;
3^4 + 3^3 + 3^2 + 3 + 43 = 163;
4^4 + 4^3 + 4^2 + 4 + 43 = 383;
5^4 + 5^3 + 5^2 + 5 + 43 = 823;
6^4 + 6^3 + 6^2 + 6 + 43 = 1597;
7^4 + 7^3 + 7^2 + 7 + 43 = 2843;
all eight are primes.
		

Crossrefs

Programs

  • Mathematica
    Select[f=k^4+k^3+k^2+k; k={0,1,2,3,4,5,6,7}; Prime[Range[2000000]], And @@ PrimeQ[#+f] &]
    Select[Prime[Range[12*10^5]],AllTrue[#+{4,30,120,340,780,1554,2800},PrimeQ]&] (* Harvey P. Dale, Apr 24 2022 *)
  • PARI
    forprime(p=1, 1e8, if( isprime(p+0)& isprime(p+4)& isprime(p+30)& isprime(p+120)& isprime(p+340)& isprime(p+780)&  isprime(p+1554)& isprime(p+2800), print1(p,", ")))

A253915 Primes p such that the polynomial k^4 + k^3 + k^2 + k + p yields primes for k = 0..8, but not for k = 9.

Original entry on oeis.org

43, 967, 11923, 213943, 2349313, 3316147, 30637567, 33421159, 39693817, 49978447, 105963769, 143405887, 148248949, 153756073, 156871549, 172981279, 187310803, 196726693, 203625283, 211977523, 220825453, 268375879, 350968543, 357834283, 414486697, 427990369
Offset: 1

Views

Author

K. D. Bajpai, Jan 18 2015

Keywords

Comments

All the terms in this sequence are congruent to 1 (mod 3).

Examples

			a(1) = 43:
0^4 + 0^3 + 0^2 + 0 + 43 =   43;
1^4 + 1^3 + 1^2 + 1 + 43 =   47;
2^4 + 2^3 + 2^2 + 2 + 43 =   73;
3^4 + 3^3 + 3^2 + 3 + 43 =  163;
4^4 + 4^3 + 4^2 + 4 + 43 =  383;
5^4 + 5^3 + 5^2 + 5 + 43 =  823;
6^4 + 6^3 + 6^2 + 6 + 43 = 1597;
7^4 + 7^3 + 7^2 + 7 + 43 = 2843;
8^4 + 8^3 + 8^2 + 8 + 43 = 4723;
all nine are primes, and
9^4 + 9^3 + 9^2 + 9 + 43 = 7423 = 13*571 is composite.
The next prime for p=43 appears for k=13, namely 30983.
		

Crossrefs

Programs

  • Mathematica
    Select[Prime[Range[118*10^5]],AllTrue[#+{0,4,30,120,340,780,1554,2800,4680},PrimeQ]&&CompositeQ[#+7380]&] (* Harvey P. Dale, Sep 10 2021 *)
  • PARI
    forprime(p=1, 1e10, if(isprime(p+4)&& isprime(p+30)&& isprime(p+120)&& isprime(p+340)&& isprime(p+780)&& isprime(p+1554)&& isprime(p+2800)&& isprime(p+4680) && !isprime(p+7380), print1(p,", ")))

Extensions

Edited by Wolfdieter Lang, Feb 20 2015
Corrected and extended by Harvey P. Dale, Sep 10 2021

A290530 Primes congruent to (11,17) mod 30.

Original entry on oeis.org

11, 17, 41, 47, 71, 101, 107, 131, 137, 167, 191, 197, 227, 251, 257, 281, 311, 317, 347, 401, 431, 461, 467, 491, 521, 557, 587, 617, 641, 647, 677, 701, 761, 797, 821, 827, 857, 881, 887, 911, 941, 947, 971, 977, 1031, 1061, 1091, 1097, 1151, 1181, 1187, 1217, 1277
Offset: 1

Views

Author

Vincenzo Librandi, Aug 05 2017

Keywords

Crossrefs

Cf. A045372, A187058 (a subsequence).

Programs

  • Magma
    [p: p in PrimesUpTo(1500) | p mod 30 in [11,17]];
  • Mathematica
    Select[Prime@Range[210], MemberQ[{11, 17}, Mod[#, 30]] &]

A385824 Primes p such that p + 10, p + 18, p + 24, p + 28 and p + 30 are also primes.

Original entry on oeis.org

13, 43, 79, 14533, 41203, 42433, 47119, 88789, 113143, 150193, 340909, 348433, 416389, 556243, 576193, 609589, 626599, 637699, 669649, 715849, 752263, 855709, 859249, 891799, 1107763, 1146763, 1189603, 1191079, 1201999, 1210369, 1225099, 1416043, 1510189, 1601599, 1893163
Offset: 1

Views

Author

Alexander Yutkin, Jul 09 2025

Keywords

Comments

Initial members of prime sextuples that correspond to the difference pattern [10, 8, 6, 4, 2]. The primes in a sextuple do not have to be consecutive.

Examples

			p=13: 13+10=23, 13+18=31, 13+24=37, 13+28=41, 13+30=43 —> prime sextuple: (13, 23, 31, 37, 41, 43).
		

Crossrefs

Cf. A000040.
Cf. A187057 [2, 4, 6, 8], A385035 [8, 6, 4, 2], A187058 [2, 4, 6, 8, 10].

Programs

  • Mathematica
    Select[Prime[Range[150000]], And @@ PrimeQ[# + {10, 18, 24, 28, 30}] &] (* Amiram Eldar, Jul 09 2025 *)
Showing 1-10 of 10 results.