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 16 results. Next

A201816 Numbers k such that 90*k + 13 is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 7, 8, 9, 12, 16, 17, 19, 22, 23, 30, 31, 35, 36, 37, 38, 40, 42, 46, 47, 49, 50, 51, 53, 58, 59, 60, 61, 63, 66, 67, 68, 74, 75, 80, 82, 84, 86, 88, 92, 95, 99, 100, 101, 103, 105, 107, 108, 112, 114, 116, 119, 121, 122, 123, 124, 126, 127
Offset: 1

Views

Author

J. W. Helkenberg, Dec 05 2011

Keywords

Comments

Looking at the format 90*k+13 modulo 9 and modulo 10 we see that all entries of A142318 have digital root 4 and last digit 3. (Reverting the process is an application of the Chinese remainder theorem.)

Crossrefs

Programs

  • Magma
    [n: n in [0..200] | IsPrime(90*n+13)]; // Vincenzo Librandi, Dec 12 2011
    
  • Maple
    a:= proc(n) option remember; local k;
           for k from 1+ `if`(n=1, -1, a(n-1))
           while not isprime(90*k+13) do od; k
        end:
    seq(a(n), n=1..100);  # Alois P. Heinz, Dec 06 2011
  • Mathematica
    Select[Range[0,4000],PrimeQ[90 #+13]&] (* Vincenzo Librandi, Dec 12 2011 *)
  • PARI
    is(n)=isprime(90*n+13) \\ Charles R Greathouse IV, Jul 12 2016

A201817 Numbers k such that 90*k + 67 is prime.

Original entry on oeis.org

0, 1, 3, 6, 8, 9, 10, 13, 14, 17, 19, 20, 23, 29, 30, 31, 33, 35, 36, 42, 44, 47, 50, 51, 56, 57, 61, 62, 63, 64, 66, 69, 70, 72, 73, 76, 77, 79, 83, 85, 90, 94, 96, 98, 100, 101, 103, 107, 108, 110, 117, 118, 120, 121, 122, 125, 127, 128, 129, 133, 138, 139
Offset: 1

Views

Author

J. W. Helkenberg, Dec 05 2011

Keywords

Comments

Looking at the format 90*k + 67 modulo 9 and modulo 10 we see that all entries of A142323 have digital root 4 and last digit 7. (Reverting the process is an application of the Chinese remainder theorem.)

Crossrefs

Programs

  • Magma
    [n: n in [0..200] | IsPrime(90*n+67)]; // Vincenzo Librandi, Dec 12 2011
    
  • Maple
    a:= proc(n) option remember; local k;
           for k from 1+ `if`(n=1, -1, a(n-1))
           while not isprime(90*k+67) do od; k
        end:
    seq(a(n), n=1..100);  # Alois P. Heinz, Dec 06 2011
  • Mathematica
    Select[Range[0,4000],PrimeQ[90 #+67]&] (* Vincenzo Librandi, Dec 12 2011 *)
  • PARI
    is(n)=isprime(90*n+67) \\ Charles R Greathouse IV, Feb 17 2017

A201820 Numbers k such that 90*k + 23 is prime.

Original entry on oeis.org

0, 1, 3, 4, 6, 7, 8, 11, 12, 13, 14, 15, 17, 19, 20, 21, 22, 25, 28, 29, 32, 34, 39, 40, 42, 45, 47, 50, 52, 53, 55, 57, 59, 63, 64, 67, 68, 70, 76, 78, 84, 85, 87, 90, 95, 96, 97, 99, 102, 103, 105, 108, 109, 110, 112, 113, 116, 119, 122, 123, 125, 129, 131
Offset: 1

Views

Author

J. W. Helkenberg, Dec 05 2011

Keywords

Comments

This sequence was generated by adding 12 Fibonacci-like sequences. Looking at the format 90*k+23 modulo 9 and modulo 10 we see that all entries of A142324 have digital root 5 and last digit 3. (Reverting the process is an application of the Chinese remainder theorem.)

Crossrefs

Programs

Formula

a(n) = (A142324(n) - 23)/90.

A201822 Numbers k such that 90*k + 77 is prime.

Original entry on oeis.org

1, 2, 3, 6, 8, 9, 10, 15, 17, 18, 19, 20, 24, 26, 29, 30, 32, 34, 37, 40, 41, 43, 45, 46, 48, 54, 58, 59, 60, 62, 65, 68, 69, 74, 75, 76, 79, 82, 83, 85, 86, 87, 89, 93, 94, 95, 97, 102, 104, 109, 111, 113, 114, 115, 117, 122, 128, 130, 131, 135, 138, 144
Offset: 1

Views

Author

J. W. Helkenberg, Dec 05 2011

Keywords

Comments

Looking at the format 90k+77 modulo 9 and modulo 10 we see that all entries of A142329 have digital root 5 and last digit 7. (Reverting the process is an application of the Chinese remainder theorem.)

Crossrefs

Programs

Formula

a(n) = (A142329(n) - 77)/90.

A202101 Numbers k such that 90*k + 59 is prime.

Original entry on oeis.org

0, 1, 2, 4, 5, 6, 11, 13, 14, 15, 16, 21, 22, 23, 25, 26, 28, 32, 34, 35, 36, 37, 40, 43, 44, 47, 51, 54, 55, 56, 57, 58, 62, 67, 69, 70, 71, 74, 76, 78, 81, 83, 89, 93, 95, 96, 99, 100, 102, 104, 107, 112, 116, 117, 120, 121, 126, 127, 128, 132, 134, 138
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 90*n+59 modulo 9 and modulo 10 we see that all entries of A142319 have digital root 5 and last digit 9. (Reverting the process is an application of the Chinese remainder theorem)

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 59] &]
  • PARI
    is(n)=isprime(90*n+59) \\ Charles R Greathouse IV, Feb 17 2017

A202104 Numbers k such that 90*k + 41 is prime.

Original entry on oeis.org

0, 1, 3, 4, 5, 8, 10, 11, 14, 16, 17, 21, 23, 26, 30, 33, 35, 37, 38, 42, 43, 44, 45, 47, 49, 52, 56, 57, 58, 59, 60, 61, 63, 64, 66, 72, 74, 75, 77, 79, 81, 85, 91, 94, 96, 98, 99, 100, 102, 103, 105, 109, 110, 113, 114, 115, 127, 131, 133, 134, 136, 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 90k+41 modulo 9 and modulo 10 we see that all entries of A142333 have digital root 5 and last digit 1. (Reverting the process is an application of the Chinese remainder theorem.) The 12 Fibonacci-like sequences are generated (via the PERL program) from the base pairs 49*91, 19*59, 37*23, 73*77, 11*61, 29*79, 47*43, 83*7, 13*17, 31*71, 49*89, 67*53.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 41] &]
  • PARI
    is(n)=isprime(90*n+41) \\ Charles R Greathouse IV, Feb 17 2017

A202105 Numbers k such that 90*k + 43 is prime.

Original entry on oeis.org

0, 2, 3, 7, 9, 11, 12, 13, 14, 16, 18, 19, 21, 23, 24, 25, 26, 27, 31, 37, 38, 40, 41, 42, 44, 45, 47, 48, 52, 53, 54, 55, 60, 62, 67, 68, 70, 74, 75, 76, 80, 81, 84, 87, 88, 89, 91, 98, 100, 101, 104, 114, 118, 119, 123, 126, 130, 131, 132, 137, 139, 142
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 90k+43 modulo 9 and modulo 10 we see that all entries of A142334 have digital root 7 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 values given in the PERL program) from the base p,q pairs 43*91, 19*7, 37*79, 73*61, 11*53, 29*17, 47*89, 83*71, 13*31, 49*67, 23*41, 59*77.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 43] &]
  • PARI
    is(n)=isprime(90*n+43) \\ Charles R Greathouse IV, Feb 17 2017

A202110 Numbers n such that 90*n + 7 is prime.

Original entry on oeis.org

0, 1, 3, 4, 5, 6, 8, 10, 11, 12, 16, 18, 22, 26, 27, 29, 30, 31, 32, 34, 39, 40, 41, 43, 44, 45, 48, 50, 51, 55, 58, 60, 65, 67, 69, 71, 73, 78, 80, 81, 83, 88, 89, 92, 93, 94, 96, 97, 100, 102, 103, 106, 109, 110, 113, 114, 115, 118, 122, 125, 127, 128, 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+7 modulo 9 and modulo 10 we see that all entries of A142315 have digital root 7 and last digit 7. (Reverting the process is an application of the Chinese remainder theorem.) The 12 Fibonacci-like sequences are generated (via the p and q values given in the PERL program) from the base p,q pairs 7*91, 19*43, 37*61, 73*79, 11*17, 29*53, 47*71, 83*89, 13*49, 31*67, 23*59, 41*77.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 7] &]
  • PARI
    is(n)=isprime(90*n+7) \\ Charles R Greathouse IV, Feb 17 2017

A202112 Numbers n such that 90n + 79 is prime.

Original entry on oeis.org

0, 3, 4, 6, 7, 11, 13, 15, 17, 18, 19, 20, 24, 29, 33, 35, 36, 38, 41, 45, 46, 52, 56, 57, 60, 61, 62, 63, 64, 68, 70, 71, 75, 81, 82, 83, 84, 89, 90, 91, 94, 95, 96, 103, 104, 106, 111, 112, 115, 119, 122, 123, 124, 125, 129, 130, 132, 133, 137, 139, 146
Offset: 1

Views

Author

J. W. Helkenberg, Dec 11 2011

Keywords

Comments

This sequence was generated by adding 14 Fibonacci-like sequences [See: PROG]. Looking at the format 90n+79 modulo 9 and modulo 10 we see that all entries of A142330 have digital root 7 and last digit 9. (Reverting the process is an application of the Chinese remainder theorem.) The 14 Fibonacci-like sequences are generated (via the p and q values given in the PERL program) from the base p,q pairs 79*91, 19*61, 37*7, 73*43, 11*89, 29*71, 47*17, 83*53, 13*13, 31*49, 67*67, 23*23, 41*59, 77*77.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 79] &]
  • PARI
    is(n)=n%90==79 && isprime(n) \\ Charles R Greathouse IV, Jun 01 2016

Formula

a(n) ~ 24n log n. - Charles R Greathouse IV, Jun 01 2016

A202113 Numbers n such that 90n + 61 is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 7, 11, 13, 14, 20, 21, 23, 24, 25, 29, 31, 34, 36, 37, 39, 43, 44, 45, 46, 50, 51, 53, 55, 56, 58, 62, 64, 67, 69, 70, 71, 77, 81, 84, 90, 93, 94, 99, 101, 102, 104, 105, 106, 108, 109, 112, 114, 116, 119, 120, 123, 125, 127, 132, 135, 136
Offset: 1

Views

Author

J. W. Helkenberg, Dec 11 2011

Keywords

Comments

This sequence was generated by adding 14 Fibonacci-like sequences [See: PROG]. Looking at the format 90n+61 modulo 9 and modulo 10 we see that all entries of A142330 have digital root 7 and last digit 1. (Reverting the process is an application of the Chinese remainder theorem.) The 14 Fibonacci-like sequences are generated (via the p and q values given in the Perl program) from the base p,q pairs 61*91, 19*79, 37*43, 73*7, 11*71, 29*89, 47*53, 83*17, 13*67, 31*31, 49*49, 23*77, 41*41, 59*59.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 200], PrimeQ[90 # + 61] &]
  • PARI
    is(n)=isprime(90*n+61) \\ Charles R Greathouse IV, Feb 17 2017
Showing 1-10 of 16 results. Next