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.

Previous Showing 21-28 of 28 results.

A062224 Numbers k such that the smoothly undulating palindromic number (75*10^k - 57)/99 is a prime.

Original entry on oeis.org

3, 17, 77, 143, 149, 513, 1079, 1415, 6249, 13265, 14579, 15293, 41657, 72941
Offset: 1

Views

Author

Patrick De Geest and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001

Keywords

Comments

Prime versus probable prime status and proofs are given in the author's table.
No further terms < 100000. - Ray Chandler, Aug 17 2011

Examples

			k=17 -> (75*10^17 - 57)/99 = 75757575757575757.

Links

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

a(13)=41657 from Ray Chandler, Nov 11 2010
a(14)=72941 from Ray Chandler, Mar 24 2011
Edited by Ray Chandler, Aug 17 2011

A062225 Numbers k such that the smoothly undulating palindromic number (78*10^k - 87)/99 is a prime.

Original entry on oeis.org

3, 5, 21, 27, 95, 2075, 2165, 3047, 3503, 16791, 34883
Offset: 1

Views

Author

Patrick De Geest and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001

Keywords

Comments

Prime versus probable prime status and proofs are given in the author's table.
No further terms < 100000. - Ray Chandler, Aug 17 2011

Examples

			k=21 -> (78*10^21 - 87)/99 = 787878787878787878787.

Links

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

Edited by Ray Chandler, Aug 17 2011

A062226 Numbers k such that the smoothly undulating palindromic number (79*10^k - 97)/99 is a prime.

Original entry on oeis.org

3, 357, 537, 1677, 3057, 51663, 66447
Offset: 1

Views

Author

Patrick De Geest and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001

Keywords

Comments

Prime versus probable prime status and proofs are given in the author's table.
No further terms < 100000. - Ray Chandler, Aug 17 2011

Examples

			k=357 -> (79*10^357 - 97)/99 = 7979797...7979797.

Links

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

a(6)=51663 from Ray Chandler, Nov 11 2010
a(7)=66447 from Ray Chandler, Jan 30 2011
Edited by Ray Chandler, Aug 17 2011

A062227 Numbers k such that the smoothly undulating palindromic number (91*10^k - 19)/99 is a prime.

Original entry on oeis.org

3, 9, 11, 17, 23, 25229
Offset: 1

Views

Author

Patrick De Geest and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001

Keywords

Comments

Prime versus probable prime status and proofs are given in the author's table.
No further terms < 100000. - Ray Chandler, Aug 17 2011

Examples

			k=23 -> (91*10^23 - 19)/99 = 91919191919191919191919.

Links

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

Edited by Ray Chandler, Aug 17 2011

A062228 Numbers k such that the smoothly undulating palindromic number (92*10^k - 29)/99 is a prime.

Original entry on oeis.org

3, 9, 195, 515, 857, 11393
Offset: 1

Views

Author

Patrick De Geest and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001

Keywords

Comments

Prime versus probable prime status and proofs are given in the author's table.
No further terms < 100000. - Ray Chandler, Aug 17 2011

Examples

			k=9 -> (92*10^9 - 29)/99 = 929292929.

Links

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

Edited by Ray Chandler, Aug 17 2011

A062229 Numbers k such that the smoothly undulating palindromic number (94*10^k - 49)/99 is a prime.

Original entry on oeis.org

5, 17, 65, 143, 551, 92981
Offset: 1

Views

Author

Patrick De Geest and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001

Keywords

Comments

Prime versus probable prime status and proofs are given in the author's table.
No further terms < 100000. - Ray Chandler, Aug 17 2011

Examples

			k=17 -> (94*10^17 - 49)/99 = 94949494949494949.

Links

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

a(6) from Ray Chandler, Jul 29 2011
Edited by Ray Chandler, Aug 17 2011

A062230 Numbers k such that the smoothly undulating palindromic number (95*10^k - 59)/99 is a prime.

Original entry on oeis.org

5, 17, 209, 1295
Offset: 1

Views

Author

Patrick De Geest and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001

Keywords

Comments

Prime versus probable prime status and proofs are given in the author's table.
No further terms < 100000. - Ray Chandler, Aug 17 2011

Examples

			k=17 -> (95*10^17 - 59)/99 = 95959595959595959.

Links

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

Edited by Ray Chandler, Aug 17 2011

A261672 Numbers k such that A037610(k) is prime.

Original entry on oeis.org

4, 7, 52, 100, 136, 388, 30940, 33250
Offset: 1

Views

Author

Felix Fröhlich, Sep 04 2015

Keywords

Comments

The terms are a subset of the terms of A016777, since a term of A037610 can only be prime if it is congruent to 1 modulo 10 and hence congruent to 1 modulo 3. If A037610(k) is congruent to 1 modulo 3, then k is congruent to 1 modulo 3 as well.
No further terms up to 10000.

Examples

			A037610(7) = 1231231 is prime, so 7 is a term of the sequence.

Crossrefs

Cf. A037610, A062209.

Programs

  • Mathematica
    Select[Range@ 500, PrimeQ@ Floor[41/333*10^#] &] (* Michael De Vlieger, Sep 07 2015 *)
  • PARI
    a037610(n) = 10^n*41\333
is(n) = ispseudoprime(a037610(n))

Extensions

a(7)-a(8) from Michael S. Branicky, Jun 28 2023
Previous Showing 21-28 of 28 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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