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.

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A272537 Numbers k such that (28*10^k + 173)/3 is prime.

Original entry on oeis.org

0, 1, 2, 3, 9, 11, 13, 15, 17, 24, 37, 44, 48, 58, 65, 104, 393, 413, 1265, 2292, 2620, 3037, 3628, 5159, 5629, 12809, 18572, 26875, 29695, 32267, 34277, 43621, 138768, 220800
Offset: 1

Views

Author

Robert Price, May 02 2016

Keywords

Comments

For k > 1, numbers k such that the digit 9 followed by k-2 occurrences of the digit 3 followed by the digits 91 is prime (see Example section).
a(35) > 3*10^5.

Examples

			3 is in this sequence because (28*10^3 + 173)/3 = 9391 is prime.
Initial terms and associated primes:
a(1) = 0, 67;
a(2) = 1, 151;
a(3) = 2, 991;
a(4) = 3, 9391;
a(5) = 9, 9333333391, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[(28*10^# + 173)/3] &]
  • PARI
    is(n)=ispseudoprime((28*10^n + 173)/3) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(33) from Robert Price, Dec 25 2019
a(34) from Robert Price, Jul 02 2024

A272622 Numbers k such that 9*10^k + 19 is prime.

Original entry on oeis.org

1, 2, 4, 5, 10, 14, 25, 34, 40, 63, 74, 129, 149, 345, 370, 425, 477, 627, 951, 1610, 2564, 2689, 4227, 7300, 7444, 8360, 16541, 21187, 25685, 31803, 89858, 92821
Offset: 1

Views

Author

Robert Price, May 03 2016

Keywords

Comments

For k > 1, numbers k such that the digit 9 followed by k-2 occurrences of the digit 0 followed by the digits 19 is prime (see Example section).
a(33) > 3*10^5.

Examples

			4 is in this sequence because 9*10^4+19 = 90019 is prime.
Initial terms and associated primes:
a(1) = 1, 109;
a(2) = 2, 919;
a(3) = 4, 90019;
a(4) = 5, 900019;
a(5) = 10, 90000000019, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[9*10^# + 19] &]
  • PARI
    is(n)=ispseudoprime(9*10^n + 19) \\ Charles R Greathouse IV, Jun 13 2017

A272717 Numbers k such that (65*10^k + 691)/9 is prime.

Original entry on oeis.org

1, 5, 7, 17, 35, 46, 56, 148, 187, 190, 256, 551, 553, 1033, 1751, 1976, 2696, 3116, 3364, 5353, 5893, 8063, 9548, 10640, 24655, 77992
Offset: 1

Views

Author

Robert Price, Aug 11 2016

Keywords

Comments

For k > 1, numbers k such that the digit 7 followed by k-2 occurrences of the digit 2 followed by the digits 99 is prime (see Example section).
a(27) > 10^5.

Examples

			5 is in this sequence because (65*10^5+691)/9 = 722299 is prime.
Initial terms and associated primes:
a(1) = 1, 149;
a(2) = 5, 722299;
a(3) = 7, 72222299;
a(4) = 17, 722222222222222299;
a(5) = 35, 722222222222222222222222222222222299, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[(65*10^#+691)/9] &]
  • PARI
    is(n)=ispseudoprime((65*10^n+691)/9) \\ Charles R Greathouse IV, Jun 13 2017

A272830 Numbers k such that (8*10^k - 29)/3 is prime.

Original entry on oeis.org

1, 2, 3, 8, 9, 10, 16, 31, 35, 79, 179, 196, 239, 376, 515, 728, 812, 1154, 2000, 2379, 2485, 3523, 3987, 5221, 5257, 5739, 17863, 59127, 106454, 125894
Offset: 1

Views

Author

Robert Price, May 07 2016

Keywords

Comments

For k > 1, numbers k such that the digit 2 followed by k-2 occurrences of the digit 6 followed by the digits 57 is prime (see Example section).
a(31) > 2*10^5.

Examples

			3 is in this sequence because (8*10^3 - 29)/3 = 2657 is prime.
Initial terms and associated primes:
a(1) = 1, 17;
a(2) = 2, 257;
a(3) = 3, 2657;
a(4) = 8, 266666657;
a(5) = 9, 2666666657, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[(8*10^# - 29)/3] &]
  • PARI
    is(n)=ispseudoprime((8*10^n-29)/3) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(29)-a(30) from Robert Price, Jul 03 2018

A272929 Numbers k such that (8*10^k - 77)/3 is prime.

Original entry on oeis.org

2, 4, 5, 6, 15, 18, 43, 45, 55, 60, 105, 128, 180, 207, 271, 479, 869, 1220, 1478, 1937, 4003, 4213, 5503, 9562, 11388, 13120, 34049, 47178, 156371, 271039
Offset: 1

Views

Author

Robert Price, May 10 2016

Keywords

Comments

For k > 1, numbers k such that the digit 2 followed by k-2 occurrences of the digit 6 followed by the digits 41 is prime (see Example section).
a(31) > 3*10^5.

Examples

			4 is in this sequence because (8*10^4 - 77)/3 = 26641 is prime.
Initial terms and associated primes:
a(1) = 2, 241;
a(2) = 4, 26641;
a(3) = 5, 266641;
a(4) = 6, 2666641;
a(5) = 15, 2666666666666641, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[1, 100000], PrimeQ[(8*10^# - 77)/3] &]
  • PARI
    lista(nn) = {for(n=1, nn, if(ispseudoprime((8*10^n - 77)/3), print1(n, ", ")));} \\ Altug Alkan, May 11 2016

Extensions

a(29) from Robert Price, Jul 07 2018
a(30) from Robert Price, Jul 02 2023

A272999 Numbers k such that (11*10^k + 49)/3 is prime.

Original entry on oeis.org

1, 2, 4, 5, 7, 10, 11, 16, 18, 21, 22, 30, 41, 69, 83, 128, 166, 190, 262, 263, 353, 496, 1398, 1793, 2806, 9722, 15733, 32420, 61095, 77909, 110496
Offset: 1

Views

Author

Robert Price, May 12 2016

Keywords

Comments

For k > 1, numbers k such that the digit 3 followed by k-2 occurrences of the digit 6 followed by the digits 83 is prime (see Example section).
a(32) > 3*10^5.

Examples

			4 is in this sequence because (11*10^4 + 49)/3 = 36683 is prime.
Initial terms and associated primes:
a(1) = 1, 53;
a(2) = 2, 383:
a(3) = 4, 36683;
a(4) = 5, 366683;
a(5) = 7, 36666683, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[(11*10^# + 49)/3] &]
  • PARI
    is(n)=ispseudoprime((11*10^n + 49)/3) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(31) from Robert Price, Jul 19 2018

A273006 Numbers k such that 88*10^k + 3 is prime.

Original entry on oeis.org

1, 2, 3, 7, 19, 21, 31, 50, 55, 151, 167, 287, 542, 603, 926, 1046, 2066, 2139, 2651, 2787, 5756, 6028, 6925, 10135, 13037, 36476, 74234, 119295
Offset: 1

Views

Author

Robert Price, Nov 09 2016

Keywords

Comments

For k > 0, numbers k such that the digits 88 followed by k-1 occurrences of the digit 0 followed by the digit 3 is prime (see Example section).
a(29) > 3*10^5.

Examples

			3 is in this sequence because 88*10^3 + 3 = 88003 is prime.
Initial terms and associated primes:
a(1) = 1, 883;
a(2) = 2, 8803;
a(3) = 3, 88003;
a(4) = 7, 880000003;
a(5) = 19, 880000000000000000003, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[88*10^# + 3] &] (* Corrected by Georg Fischer, Jul 22 2019 *)
  • PARI
    is(n)=ispseudoprime(88*10^n + 3) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(28) from Robert Price, May 03 2020

A273042 Numbers k such that (28*10^k + 191)/3 is prime.

Original entry on oeis.org

0, 1, 2, 3, 5, 6, 9, 10, 33, 49, 92, 109, 548, 757, 814, 1289, 1460, 1644, 2782, 6355, 8028, 9276, 9366, 9765, 12002, 12089, 14491, 16180, 29102, 30989, 151682, 183403, 190105, 253210
Offset: 1

Views

Author

Robert Price, May 13 2016

Keywords

Comments

For k > 1, numbers k such that the digit 9 followed by k-2 occurrences of the digit 3 followed by the digits 97 is prime (see Example section).
a(35) > 3*10^5.

Examples

			3 is in this sequence because (28*10^3 + 191)/3 = 9397 is prime.
Initial terms and associated primes:
a(1) = 0, 73;
a(2) = 1, 157:
a(3) = 2, 997;
a(4) = 3, 9397;
a(5) = 5, 933397, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[(28*10^# + 191)/3] &]
  • PARI
    is(n)=ispseudoprime((28*10^n + 191)/3) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(31)-a(33) from Robert Price, Feb 27 2020
a(34) from Robert Price, Jul 12 2023

A273063 Numbers k such that (112*10^k + 17)/3 is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 8, 44, 53, 79, 89, 95, 120, 224, 259, 290, 488, 725, 821, 1815, 3096, 3100, 3404, 5909, 8054, 11879, 17298, 25588, 41516, 127324, 191900
Offset: 1

Views

Author

Robert Price, May 14 2016

Keywords

Comments

For k > 0, numbers k such that the digits 37 followed by k-1 occurrences of the digit 3 followed by the digit 9 is prime (see Example section).
a(31) > 3*10^5.

Examples

			3 is in this sequence because (112*10^3+17)/3 = 37339 is prime.
Initial terms and associated primes:
a(1) = 0, 43;
a(2) = 1, 379:
a(3) = 2, 3739;
a(4) = 3, 37339;
a(5) = 4, 373339, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[(112*10^# + 17)/3] &]
  • PARI
    is(n)=ispseudoprime((112*10^n + 17)/3) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(29)-a(30) from Robert Price, Mar 05 2020

A273097 Numbers k such that 4*10^k + 87 is prime.

Original entry on oeis.org

1, 2, 4, 5, 13, 25, 27, 32, 37, 38, 40, 45, 57, 80, 91, 151, 214, 441, 644, 764, 797, 1222, 2329, 2931, 4324, 21794, 22396, 24041, 46420, 51489, 55165, 126625
Offset: 1

Views

Author

Robert Price, May 15 2016

Keywords

Comments

For k > 1, numbers k such that the digit 4 followed by k-2 occurrences of the digit 0 followed by the digits 87 is prime (see Example section).
a(33) > 3*10^5.

Examples

			4 is in this sequence because 4*10^4 + 87 = 40087 is prime.
Initial terms and associated primes:
a(1) = 1, 127:
a(2) = 2, 487;
a(3) = 4, 40087;
a(4) = 5, 400087;
a(5) = 13, 40000000000087, etc.

Links

Crossrefs

Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[4*10^# + 87] &]
  • PARI
    is(n)=ispseudoprime(4*10^n + 87) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(32) from Robert Price, Aug 15 2018
Previous Showing 61-70 of 505 results. Next

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