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 1-6 of 6 results.

A202115 Numbers n such that 90n + 17 is prime.

Original entry on oeis.org

0, 1, 2, 5, 6, 7, 9, 12, 13, 14, 15, 18, 21, 22, 23, 25, 26, 27, 32, 35, 36, 37, 39, 40, 42, 46, 48, 50, 53, 54, 55, 57, 58, 60, 61, 65, 67, 70, 76, 77, 79, 81, 83, 84, 86, 88, 90, 92, 93, 97, 98, 104, 105, 111, 116, 123, 124, 127, 130, 131, 132, 133, 137
Offset: 1

Views

Author

J. W. Helkenberg, Dec 11 2011

Keywords

Crossrefs

Programs

  • Maple
    select(t -> isprime(90*t+17),[$0..1000]); # Robert Israel, Sep 02 2014
  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 17] &]
  • PARI
    is(n)=isprime(90*n+17) \\ Charles R Greathouse IV, Feb 20 2017

A202114 Numbers n such that 90n + 53 is prime.

Original entry on oeis.org

0, 2, 5, 6, 7, 8, 9, 10, 13, 16, 17, 24, 26, 29, 30, 31, 33, 35, 42, 43, 44, 47, 48, 49, 51, 52, 55, 58, 64, 65, 68, 69, 70, 75, 77, 80, 82, 83, 85, 86, 87, 91, 93, 94, 96, 97, 99, 103, 104, 112, 113, 114, 120, 124, 126, 127, 132, 134, 135, 138, 140, 141
Offset: 1

Views

Author

J. W. Helkenberg, Dec 11 2011

Keywords

Comments

This sequence was generated by adding 12 Fibonacci-like sequences [See: PROG]. Looking at the format 90n+53 modulo 9 and modulo 10 we see that all entries of A142316 have digital root 8 and last digit 3. (Reverting the process is an application of the Chinese remainder theorem.) The 12 Fibonacci-like sequences are generated (via the p and q "seed" values entered into the PERL program) from the base p,q pairs 53*91, 19*17, 37*89, 73*71, 11*13, 29*67, 47*49, 83*31, 23*61, 41*43, 59*7, 77*79.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 53] &]
  • PARI
    is(n)=isprime(90*n+53) \\ Charles R Greathouse IV, Feb 20 2017

A202116 Numbers n such that 90n + 89 is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 7, 8, 13, 15, 17, 18, 20, 21, 22, 25, 28, 29, 30, 31, 32, 36, 41, 44, 45, 46, 48, 51, 55, 58, 59, 62, 64, 65, 66, 69, 70, 72, 73, 77, 78, 83, 84, 86, 87, 88, 92, 97, 99, 105, 106, 107, 111, 112, 113, 116, 118, 119, 120, 121, 122, 123, 127, 129
Offset: 1

Views

Author

J. W. Helkenberg, Dec 11 2011

Keywords

Comments

This sequence was generated by adding 12 Fibonacci-like sequences [See: PROG?]. Looking at the format 90n+89 modulo 9 and modulo 10 we see that all entries of A142335 have digital root 8 and last digit 9. (Reverting the process is an application of the Chinese remainder theorem.) The 12 Fibonacci-like sequences are generated (via the p and q "seed" values entered into the PERL program) from the base p,q pairs 89*91, 19*71, 37*17, 73*53, 11*49, 29*31, 47*67, 83*13, 23*43, 41*79, 59*61, 77*7.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 89] &]
  • PARI
    is(n)=isprime(90*n+89) \\ Charles R Greathouse IV, Jun 06 2017

A255512 Numbers k such that 60*k+41, 90*k+61 and 150*k+101 are all prime.

Original entry on oeis.org

0, 1, 4, 7, 21, 24, 31, 43, 46, 70, 99, 108, 109, 112, 154, 158, 176, 213, 218, 234, 238, 267, 273, 311, 319, 337, 381, 515, 518, 519, 528, 540, 658, 680, 689, 704, 736, 739, 752, 781, 837, 889, 1012, 1071, 1165, 1170, 1180, 1197, 1233, 1331, 1344, 1373, 1379
Offset: 1

Views

Author

Vincenzo Librandi, Feb 24 2015

Keywords

Crossrefs

Cf. A202113.
Cf. A255441 (Carmichael numbers of the form (60k+41)*(90k+61)*(150k+101)).

Programs

  • Magma
    [n: n in [0..2000]| IsPrime(60*n+41) and IsPrime(90*n+61) and IsPrime(150*n+101)];
    
  • Mathematica
    Select[Range[0, 1400], PrimeQ[60 # + 41] && PrimeQ[90 # + 61] && PrimeQ[150 # + 101] &]
    Select[Range[0,1500],AllTrue[{60#+41,90#+61,150#+101},PrimeQ]&] (* Harvey P. Dale, Jan 13 2024 *)
  • PARI
    is(k) = isprime(60*k + 41) && isprime(90*k + 61) && isprime(150*k + 101); \\ Amiram Eldar, Apr 24 2024

A202129 Numbers n such that 90n + 71 is prime.

Original entry on oeis.org

0, 2, 4, 5, 7, 9, 10, 11, 12, 16, 17, 20, 23, 26, 28, 31, 33, 35, 38, 39, 40, 41, 42, 46, 48, 49, 52, 54, 55, 59, 60, 62, 63, 66, 67, 72, 76, 77, 82, 83, 87, 89, 90, 101, 103, 104, 105, 108, 111, 112, 114, 117, 118, 119, 125, 126, 129, 133, 137, 138, 140
Offset: 1

Views

Author

J. W. Helkenberg, Dec 11 2011

Keywords

Comments

This sequence was generated by adding 12 Fibonacci-like sequences [See: PROG?]. Looking at the format 90n+71 modulo 9 and modulo 10 we see that all entries of A142325 have digital root 8 and last digit 1. (Reverting the process is an application of the Chinese remainder theorem.) The 12 Fibonacci-like sequences are generated (via the p and q "seed" values entered into the Perl program) from the base p,q pairs 71*91, 19*89, 37*53, 73*13, 11*31, 29*49, 47*13, 83*67, 23*7, 41*61, 59*79, 77*43.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 71] &]
  • PARI
    is(n)=isprime(90*n+71) \\ Charles R Greathouse IV, Jun 13 2017

A224860 Numbers n such that 90*n + 59 and 90*n + 61 are twin prime.

Original entry on oeis.org

0, 1, 2, 4, 6, 11, 13, 14, 21, 23, 25, 34, 36, 37, 43, 44, 51, 55, 56, 58, 62, 67, 69, 70, 71, 81, 93, 99, 102, 104, 112, 116, 120, 127, 132, 153, 155, 161, 169, 170, 188, 197, 200, 212, 242, 245, 252, 259, 265, 268, 279, 286, 291, 296, 298, 300, 302, 307
Offset: 1

Views

Author

J. W. Helkenberg, Jul 22 2013

Keywords

Comments

All matching entries of A202101 and A202113 are twin prime.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 499], PrimeQ[90# + 59] && PrimeQ[90# + 61] &]

Extensions

More terms from Bruno Berselli, Jul 23 2013
Showing 1-6 of 6 results.