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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A262661 Minimal nested palindromic base-8 primes with seed 1; see Comments.

Original entry on oeis.org

1, 111, 1411141, 12141114121, 10412141114121401, 11610412141114121401611, 171161041214111412140161171, 303171161041214111412140161171303, 3230317116104121411141214016117130323, 71323031711610412141114121401611713032317
Offset: 1

Views

Author

Clark Kimberling, Oct 31 2015

Keywords

Comments

Using only base-8 digits 0,1,2,3,4,5,6,7 let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime have a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic base-8 primes with seed s.

Examples

			a(3) = 1411141 is the least base-8 prime having a(2) = 111 in its middle. Triangular format:
           1
          111
        1411141
      12141114121
   10412141114121401
11610412141114121401611
		

Crossrefs

Cf. A261881 (base 10), A262662, A262627.

Programs

  • Mathematica
    s = {1}; base = 8; z = 20; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#, base]], base]] &];
    AppendTo[s, FromDigits[IntegerDigits[tmp, base]]], {z}]; s  (* A262661 *)
    Map[FromDigits[ToString[#], base] &, s]  (* A262662 *)
    (* Peter J. C. Moses, Sep 01 2015 *)

A260250 Minimal nested palindromic primes with seed 000000000.

Original entry on oeis.org

1300000000031, 713000000000317, 1471300000000031741, 12147130000000003174121, 3121471300000000031741213, 1213121471300000000031741213121, 33121312147130000000003174121312133, 323312131214713000000000317412131213323
Offset: 2

Views

Author

Clark Kimberling, Sep 24 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime having a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s. (For A260250, the seed is not an integer, so that the offset is 2.)

Examples

			As a triangle:
           000000000
         1300000000031
        713000000000317
      1471300000000031741
    12147130000000003174121,
   3121471300000000031741213
1213121471300000000031741213121,
		

Crossrefs

Cf. A261881.

Programs

  • Mathematica
    s0 = "000000000"; s = {ToExpression[s0]};Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s], 10, Max[StringLength[s0],Length[IntegerDigits[Last[s]]]]], Reverse[#]]&[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {10}]; s0 <> ", " <> StringTake[ToString[Rest[s]], {2, -2}]
    (* Peter J. C. Moses, Sep 23 2015 *)

A260459 Minimal nested palindromic primes with seed 010.

Original entry on oeis.org

30103, 333010333, 33330103333, 9333301033339, 12933330103333921, 121293333010333392121, 3812129333301033339212183, 15381212933330103333921218351, 101538121293333010333392121835101, 3910153812129333301033339212183510193
Offset: 2

Views

Author

Clark Kimberling, Sep 24 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime having a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s. (For A260459, the seed is not an integer, so that the offset is 2.)

Examples

			As a triangle:
           010
          30103
        333010333
       33330103333
      9333301033339
    12933330103333921
  121293333010333392121
3812129333301033339212183
		

Crossrefs

Cf. A261881.

Programs

  • Mathematica
    s0 = "010"; s = {ToExpression[s0]};Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s], 10, Max[StringLength[s0],Length[IntegerDigits[Last[s]]]]], Reverse[#]]&[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {10}]; s0 <> ", " <> StringTake[ToString[Rest[s]], {2, -2}]
    (* Peter J. C. Moses, Sep 23 2015 *)

A261820 Minimal nested palindromic primes with seed 111.

Original entry on oeis.org

111, 1311131, 113111311, 91131113119, 9911311131199, 12991131113119921, 771299113111311992177, 1077129911311131199217701, 11107712991131113119921770111, 101110771299113111311992177011101, 107101110771299113111311992177011101701
Offset: 1

Views

Author

Clark Kimberling, Sep 24 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime having a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s.

Examples

			As a triangle:
        111
      1311131
     113111311
    91131113119
   9911311131199
  12991131113119921
771299113111311992177
		

Crossrefs

Cf. A261881.

Programs

  • Mathematica
    s0 = "111"; s = {ToExpression[s0]};Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s], 10, Max[StringLength[s0],Length[IntegerDigits[Last[s]]]]], Reverse[#]]&[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {10}]; s0 <> ", " <> StringTake[ToString[Rest[s]], {2, -2}]
    (* Peter J. C. Moses, Sep 23 2015 *)

A261821 Minimal nested palindromic primes with seed 4.

Original entry on oeis.org

4, 11411, 1114111, 18111411181, 741811141118147, 1674181114111814761, 90167418111411181476109, 3901674181114111814761093, 14390167418111411181476109341, 9143901674181114111814761093419, 75914390167418111411181476109341957
Offset: 1

Views

Author

Clark Kimberling, Sep 23 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime have a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s.

Examples

			As a triangle:
.........4
.......11411
......1114111
....18111411181
..741811141118147
1674181114111814761
		

Crossrefs

Cf. A261881 (seed 0, with guide to related sequences).

Programs

  • Mathematica
    s = {4}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s
    (* Peter J. C. Moses, Sep 01 2015 *)

A261822 Minimal nested palindromic primes with seed 5.

Original entry on oeis.org

5, 151, 31513, 3315133, 11331513311, 191133151331191, 9919113315133119199, 39991911331513311919993, 353999191133151331191999353, 13539991911331513311919993531, 741353999191133151331191999353147
Offset: 1

Views

Author

Clark Kimberling, Sep 23 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime have a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s.

Examples

			As a triangle:
.......5
......151
.....31513
....3315133
..11331513311
191133151331191
		

Crossrefs

Cf. A261881 (seed 0, with guide to related sequences).

Programs

  • Mathematica
    s = {5}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s
    (* Peter J. C. Moses, Sep 01 2015 *)

A261823 Minimal nested palindromic primes with seed 6.

Original entry on oeis.org

6, 10601, 3106013, 19310601391, 3193106013913, 30319310601391303, 3303193106013913033, 333031931060139130333, 33330319310601391303333, 303333031931060139130333303, 1130333303193106013913033330311, 19113033330319310601391303333031191
Offset: 1

Views

Author

Clark Kimberling, Sep 23 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime have a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s.

Examples

			As a triangle:
........6
......10601
.....3106013
...19310601391
..3193106013913
30319310601391303
		

Crossrefs

Cf. A261881 (seed 0, with guide to related sequences).

Programs

  • Mathematica
    s = {6}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s
    (* Peter J. C. Moses, Sep 01 2015 *)

A261824 Minimal nested palindromic primes with seed 7.

Original entry on oeis.org

7, 373, 93739, 129373921, 3212937392123, 34321293739212343, 353432129373921234353, 1335343212937392123435331, 1171335343212937392123435331711, 1051171335343212937392123435331711501, 74105117133534321293739212343533171150147
Offset: 1

Views

Author

Clark Kimberling, Sep 23 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime have a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s.

Examples

			As a triangle:
........7
.......373
......93739
....129373921
..3212937392123
34321293739212343
		

Crossrefs

Cf. A261881 (seed 0, with guide to related sequences).

Programs

  • Mathematica
    s = {7}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s
    (* Peter J. C. Moses, Sep 01 2015 *)

A261825 Minimal nested palindromic primes with seed 8.

Original entry on oeis.org

8, 181, 1218121, 15121812151, 111512181215111, 3311151218121511133, 133111512181215111331, 1113311151218121511133111, 1141113311151218121511133111411, 73114111331115121812151113311141137, 30273114111331115121812151113311141137203
Offset: 1

Views

Author

Clark Kimberling, Sep 23 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime have a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s.

Examples

			As a triangle:
.........8
........181
......1218121
....15121812151
..111512181215111
3311151218121511133
		

Crossrefs

Cf. A261881 (seed 0, with guide to related sequences).

Programs

  • Mathematica
    s = {8}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s
    (* Peter J. C. Moses, Sep 01 2015 *)

A261826 Minimal nested palindromic primes with seed 9.

Original entry on oeis.org

9, 191, 71917, 147191741, 3914719174193, 139147191741931, 7213914719174193127, 33721391471917419312733, 9337213914719174193127339, 1719337213914719174193127339171, 11171933721391471917419312733917111, 1111719337213914719174193127339171111
Offset: 1

Views

Author

Clark Kimberling, Sep 23 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime have a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s.

Examples

			As a triangle:
.......9
......191
.....71917
...147191741
.3914719174193
139147191741931
		

Crossrefs

Cf. A261881 (seed 0, with guide to related sequences).

Programs

  • Mathematica
    s = {9}; Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s]], Reverse[#]] &[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {15}]; s
    (* Peter J. C. Moses, Sep 01 2015 *)
Previous Showing 21-30 of 36 results. Next