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 1-5 of 5 results.

A330366 Prime numbers p_k such that p_k == 1 (mod 10) and p_(k+1) == 1 (mod 10).

Original entry on oeis.org

181, 241, 421, 631, 691, 811, 1021, 1051, 1171, 1471, 1801, 2521, 2731, 3001, 3361, 3571, 4201, 4231, 4261, 4831, 4861, 5011, 5351, 5581, 5701, 5791, 6091, 6121, 6301, 6481, 6491, 6691, 6781, 7321, 8101, 8221, 8821, 8941, 9421, 9511, 9931, 10141, 10321, 10771, 11161, 11971
Offset: 1

Views

Author

A.H.M. Smeets, Dec 12 2019

Keywords

Crossrefs

Cf. A030430 (1, any), this sequence (1, 1), A331555 (1, 3), A331324 (1, 7), A030431 (3, any), A030432 (7, any), A030433 (9, any) [where (a, b) means p_k == a (mod 10) and p_(k+1) == b (mod 10)].

Programs

  • Magma
    [p: p in PrimesUpTo(14000)| (p mod 10 eq 1) and (NextPrime(p) mod 10 eq 1)]; // Marius A. Burtea, Jan 20 2020
  • Mathematica
    First @ Transpose @ Select[Partition[Select[Range[13500], PrimeQ], 2, 1], Mod[First[#], 10] == 1 && Mod[Last[#],10] == 1 &] (* Amiram Eldar, Jan 20 2020 *)
  • PARI
    isok(p) = isprime(p) && ((p % 10)==1) && ((nextprime(p+1) % 10) == 1); \\ Michel Marcus, Jan 20 2020
    

A331324 Prime numbers p_k such that p_k == 1 (mod 10) and p_(k+1) == 7 (mod 10).

Original entry on oeis.org

31, 61, 131, 151, 251, 271, 331, 541, 571, 601, 751, 941, 971, 991, 1181, 1231, 1291, 1321, 1361, 1601, 1621, 1741, 1831, 1861, 1901, 2011, 2131, 2221, 2251, 2281, 2341, 2351, 2371, 2411, 2441, 2551, 2671, 2791, 2851, 3061, 3121, 3181, 3301, 3391, 3511, 3541, 3631, 3691, 3761, 3911
Offset: 1

Views

Author

A.H.M. Smeets, Jan 20 2020

Keywords

Crossrefs

Cf. A030430 (1, any), A330366 (1, 1), A331555 (1, 3), this sequence (1, 7), A030431 (3, any), A030432 (7, any), A030433 (9, any) [where (a, b) means p_k == a (mod 10) and p_(k+1) == b (mod 10)].

Programs

  • Magma
    [p: p in PrimesUpTo(4400)| (p mod 10 eq 1) and (NextPrime(p) mod 10 eq 7)]; // Marius A. Burtea, Jan 20 2020
  • Mathematica
    First @ Transpose @ Select[Partition[Select[Range[4500], PrimeQ], 2, 1], Mod[First[#], 10] == 1 && Mod[Last[#],10] == 7 &] (* Amiram Eldar, Jan 20 2020 *)
    Prime[#]&/@SequencePosition[Mod[Prime[Range[600]],10],{1,7}][[All,1]] (* Harvey P. Dale, Oct 17 2022 *)

A332674 Prime numbers p_k such that p_k == 1 (mod 10) and p_(k+1) == 9 (mod 10).

Original entry on oeis.org

401, 491, 701, 761, 911, 1381, 1571, 2161, 2531, 2741, 2861, 2971, 3011, 3041, 3221, 3271, 3491, 3701, 3881, 4751, 5051, 5171, 6011, 6221, 6451, 6521, 6581, 7151, 7351, 7621, 7691, 8171, 8191, 8681, 8761, 8971, 9311, 9941, 10151, 10391, 10531, 10631, 10691
Offset: 1

Views

Author

A.H.M. Smeets, Feb 19 2020

Keywords

Crossrefs

Cf. A030430 (1, any), A330366 (1, 1), A331555 (1, 3), A331324 (1, 7), this sequence (1, 9), A030431 (3, any), A332675 (3, 1), A332676 (3, 3), A030432 (7, any), A030433 (9, any) [where (a, b) means p_k == a (mod 10) and p_(k+1) == b (mod 10)].

Programs

  • Maple
    select(p -> isprime(p) and nextprime(p) mod 10 = 9, [seq(i,i=1..20000,10)]); # Robert Israel, Jun 10 2024
  • Mathematica
    First @ Transpose @ Select[Partition[Select[Range[12500], PrimeQ], 2, 1], Mod[First[#], 10] == 1 && Mod[Last[#], 10] == 9 &] (* Amiram Eldar, Feb 19 2020 *)
  • PARI
    forprime(p=1+o=2,1e4,p%10==9&&o%10==1&&print1(o",");o=p) \\ M. F. Hasler, Feb 19 2020

A332676 Prime numbers p_k such that p_k == 3 (mod 10) and p_(k+1) == 3 (mod 10).

Original entry on oeis.org

283, 1153, 1723, 2053, 2143, 3413, 3583, 3823, 3853, 4243, 4273, 4363, 4483, 4663, 5323, 5903, 6133, 6163, 6343, 6553, 6793, 6803, 7253, 7963, 8243, 8353, 8543, 8563, 8783, 8893, 9283, 9403, 10223, 10303, 10433, 10993, 11093, 11383, 12253, 12703, 13063, 13513, 13933, 14293, 14983
Offset: 1

Views

Author

A.H.M. Smeets, Feb 19 2020

Keywords

Crossrefs

Cf. A030430 (1, any), A330366 (1, 1), A331555 (1, 3), A331324 (1, 7), A332674 (1, 9), A030431 (3, any), A332675 (3, 1), this sequence (3, 3), A030432 (7, any), A030433 (9, any) [where (a, b) means p_k == a (mod 10) and p_(k+1) == b (mod 10)].

Programs

  • Maple
    filter:= t -> isprime(t) and nextprime(t) mod 10 = 3:
    select(filter, [seq(i,i=3..20000,10)]); # Robert Israel, May 08 2020
  • Mathematica
    First @ Transpose @ Select[Partition[Select[Range[20000], PrimeQ], 2, 1], Mod[First[#], 10] == 3 && Mod[Last[#], 10] == 3 &] (* Amiram Eldar, Feb 19 2020 *)

A332675 Prime numbers p_k such that p_k == 3 (mod 10) and p_(k+1) == 1 (mod 10).

Original entry on oeis.org

523, 683, 743, 983, 1163, 1193, 1373, 1523, 1733, 1823, 1913, 2003, 2153, 2213, 2243, 2273, 2503, 2663, 2843, 3623, 3803, 4373, 4423, 4463, 4583, 4603, 4703, 4733, 4943, 5483, 5573, 5693, 5783, 5813, 5953, 6113, 6143, 6203, 6473, 6833, 6983, 7393, 7433, 7673, 7883, 8093, 8513, 8573
Offset: 1

Views

Author

A.H.M. Smeets, Feb 19 2020

Keywords

Crossrefs

Cf. A030430 (1, any), A330366 (1, 1), A331555 (1, 3), A331324 (1, 7), A332674 (1, 9), A030431 (3, any), this sequence (3, 1), A332676 (3, 3), A030432 (7, any), A030433 (9, any) [where (a, b) means p_k == a (mod 10) and p_(k+1) == b (mod 10)].

Programs

  • Mathematica
    First @ Transpose @ Select[Partition[Select[Range[10^4], PrimeQ], 2, 1], Mod[First[#], 10] == 3 && Mod[Last[#], 10] == 1 &] (* Amiram Eldar, Feb 19 2020 *)
Showing 1-5 of 5 results.