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 1-8 of 8 results.

A105982 Near-repdigit primes with at least two 2's as the repeated digit.

Original entry on oeis.org

223, 227, 229, 2221, 22229, 22222223, 222222227, 22222222223, 22222222222229, 222222222222227, 222222222222222221, 2222222222222222222222222227, 222222222222222222222222222222222223
Offset: 1

Views

Author

Shyam Sunder Gupta, Apr 29 2005

Keywords

Examples

			a(2)=227 is a term because all digits are equal to 2 except one.
		

Crossrefs

Extensions

Name clarified by Robert Price, Sep 10 2023

A105976 Near-repdigit primes with at least two 8's as the repeated digit.

Original entry on oeis.org

881, 883, 887, 8887, 88883, 888887, 88888883, 888888883, 888888887, 888888888887, 88888888888889, 888888888888883, 88888888888888889, 8888888888888888881, 88888888888888888888888888888888889
Offset: 1

Views

Author

Shyam Sunder Gupta, Apr 29 2005

Keywords

Examples

			a(2)=883 is a term because all digits are equal to 8 except one.
		

Crossrefs

Extensions

Name clarified by Robert Price, Sep 10 2023

A105978 Near-repdigit primes with at least two 6's as the repeated digit.

Original entry on oeis.org

661, 6661, 666667, 66666667, 666666667, 6666666661, 66666666667, 666666666666666661, 66666666666666666667, 666666666666666666661, 6666666666666666666661, 66666666666666666666667, 6666666666666666666666666661
Offset: 1

Views

Author

Shyam Sunder Gupta, Apr 29 2005

Keywords

Examples

			a(2)=6661 is a term because all digits are equal to 6 except one.
		

Crossrefs

Programs

  • Mathematica
    Select[FromDigits/@Flatten[Table[PadLeft[{pd},n,6],{pd,{1,7}},{n,3,30}],1],PrimeQ]//Sort (* Harvey P. Dale, Sep 01 2021 *)

Extensions

More terms from Harvey P. Dale, Sep 01 2021
Name clarified by Robert Price, Sep 10 2023

A105980 Near-repdigit primes with at least two 4's as the repeated digit.

Original entry on oeis.org

443, 449, 4441, 4447, 44449, 444443, 444449, 444444443, 4444444447, 44444444441, 444444444443, 44444444444444444447, 44444444444444444444444447, 4444444444444444444444444441, 444444444444444444444444444443
Offset: 1

Views

Author

Shyam Sunder Gupta, Apr 29 2005

Keywords

Examples

			a(2)=449 is a term because all digits are equal to 4 except one.
		

Crossrefs

Programs

  • Mathematica
    Select[Flatten[Table[FromDigits[PadLeft[{n},x,4]],{x,3,30},{n,{1,3,7,9}}]],PrimeQ] (* Harvey P. Dale, Feb 18 2018 *)

Extensions

More terms from Harvey P. Dale, Feb 18 2018
Name clarified by Robert Price, Sep 10 2023

A105979 Near-repdigit primes with at least two 5's as the repeated digit.

Original entry on oeis.org

557, 5557, 555557, 55555553, 55555559, 5555555557, 555555555551, 555555555559, 5555555555551, 555555555555557, 555555555555555559, 5555555555555555555557, 55555555555555555555555553, 55555555555555555555555559, 55555555555555555555555555555559
Offset: 1

Views

Author

Shyam Sunder Gupta, Apr 29 2005

Keywords

Examples

			5557 is a term because all digits are equal to 5 except one.
		

Crossrefs

Extensions

Name clarified by Robert Price, Sep 10 2023

A365592 Near-repdigit primes with at least two 1's as the repeated digit.

Original entry on oeis.org

113, 1117, 11113, 11117, 11119, 111119, 11111117, 11111119, 111111113, 11111111113, 11111111111111119, 1111111111111111111, 11111111111111111111111, 11111111111111111111117, 111111111111111111111113, 11111111111111111111111111117
Offset: 1

Views

Author

Robert Price, Sep 10 2023

Keywords

Examples

			1117 is a term because all digits are equal to 1 except the last one.
		

Crossrefs

A365596 Near-repdigit primes with at least two 3's as the repeated digit.

Original entry on oeis.org

331, 337, 3331, 33331, 333331, 333337, 3333331, 33333331, 333333333333333331, 3333333333333333333333333333333333333331, 3333333333333333333333333333333333333333333337, 33333333333333333333333333333333333333333333333331
Offset: 1

Views

Author

Robert Price, Sep 10 2023

Keywords

Examples

			3331 is a term because all digits are equal to 3 except the last one.
		

Crossrefs

A365598 Near-repdigit primes with at least two 9's as the repeated digit, and ending in a distinct digit.

Original entry on oeis.org

991, 997, 99991, 9999991, 99999999999999997, 999999999999999999999999999999991, 999999999999999999999999999999999999999999991
Offset: 1

Views

Author

Robert Price, Sep 10 2023

Keywords

Comments

The usual definition of near-repdigit prime allows the distinct digit to be in any position, see A105975 for that (super) sequence.

Examples

			99991 is a term because all digits are equal to 9 except the last one.
		

Crossrefs

Programs

  • Maple
    R:= NULL: count:= 0:
    for n from 3 to 999 do
      for d in [9,3] do
        if isprime(10^n - d) then
          R:= R, 10^n-d; count:= count+1;
        fi
    od od:
    R;

Extensions

Definition corrected by M. F. Hasler, Jun 20 2025
Showing 1-8 of 8 results.