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 1-3 of 3 results.

A168417 Primes q for which 1 concatenated with q^3 (A168327) is prime.

Original entry on oeis.org

3, 13, 103, 109, 139, 163, 181, 211, 379, 457, 463, 1021, 1087, 1123, 1201, 1249, 1303, 1381, 1579, 1597, 1609, 1699, 1861, 1873, 1987, 2011, 2029, 2053, 2143, 2221, 2281, 2341, 2473, 2503, 2557, 2731, 2857, 3061, 3067, 3217, 3253, 3271, 3319, 3331, 3517
Offset: 1

Views

Author

Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Nov 25 2009

Keywords

Comments

It is conjectured that this sequence is infinite.

Examples

			(1) "1 3^3"=10^2+3^3=127=prime(31) gives a(1)=3=prime(2)
(2) "1 103^3"=10^7+103^3=11092727=prime(732258) gives a(3)=103=prime(27)
		

References

  • Harold Davenport, Multiplicative Number Theory, Springer-Verlag New-York 1980
  • Leonard E. Dickson: History of the Theory of numbers, vol. I, Dover Publications 2005

Crossrefs

A168147 Primes of the form p = 1 + 10*n^3 for a natural number n
A168327 Primes of concatenated form p= "1 n^3"
A168375 Natural numbers n for which the concatenation p= "1 n^3" is prime

Programs

  • Mathematica
    Select[Prime[Range[500]],PrimeQ[FromDigits[Join[{1},IntegerDigits[ #^3]]]]&] (* Harvey P. Dale, Jan 21 2013 *)

Extensions

Edited and extended by Charles R Greathouse IV, Apr 23 2010

A168540 Natural numbers n for which 100n^3 + 27 is prime.

Original entry on oeis.org

1, 2, 4, 5, 7, 13, 17, 25, 29, 32, 44, 55, 61, 76, 77, 80, 92, 106, 109, 112, 116, 121, 124, 136, 137, 142, 143, 149, 152, 154, 158, 161, 169, 170, 178, 190, 191, 196, 200, 208, 221, 223, 224, 227, 230, 245, 254, 259, 260, 262
Offset: 1

Views

Author

Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Nov 29 2009

Keywords

Comments

It is conjectured that sequence is infinite.

Examples

			(1) 3^3+10^2*1^3=127=prime(31) gives a(1)=1
(2) 3^3+10^2*2^3=827=prime(144) gives a(2)=2
(3) 3^3+10^2*13^3=219727=prime(19588) gives a(6)=13
		

References

  • Leonard E. Dickson: History of the Theory of numbers, vol. I, Dover Publications 2005
  • Friedhelm Padberg, Elementare Zahlentheorie, Spektrum Akademischer Verlag, 2. Auflage 1991

Crossrefs

Cf. A168147 Primes of the form p = 1 + 10*n^3 for a natural number n
Cf. A168327 Primes of concatenated form p= "1 n^3"
Cf. A168375 Natural numbers n for which the concatenation p= "1 n^3"is prime

Programs

  • Mathematica
    Select[Range[300],PrimeQ[100#^3+27]&] (* Harvey P. Dale, May 10 2013 *)

Extensions

Edited by Charles R Greathouse IV, Apr 28 2010

A169586 Primes p in A168540 for which q = 3^3 + 10^2*p^3 (A168487) is prime.

Original entry on oeis.org

2, 5, 7, 13, 17, 29, 61, 109, 137, 149, 191, 223, 227, 269, 311, 331, 337, 359, 389, 397, 409, 433, 457, 467, 491, 587, 619, 653, 661, 709, 727
Offset: 1

Views

Author

Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Dec 02 2009

Keywords

Comments

It is conjectured that sequence is infinite

Examples

			(1) 3^3+10^2*2^3=827=prime(144) gives a(1)=2=prime(1)
(2) 3^3+10^2*5^3=12527=prime(1496) gives a(2)=5=prime(3)
(3) 3^3+10^2*13^3=219727=prime(19588) gives a(4)=13=prime(6)
		

References

  • Leonard E. Dickson: History of the Theory of numbers, vol. I, Dover Publications 2005
  • Theo Kempermann, Zahlentheoretische Kostproben, Harri Deutsch, 2. aktualisierte Auflage 2005
  • Arnold Scholz, Bruno Schoeneberg: Einführung in die Zahlentheorie, Walter de Gruyter, 5. Auflage 1973

Crossrefs

A000040 The prime numbers
A167535 Concatenation of two square numbers which give a prime
A168147 Primes of the form p = 1 + 10*n^3 for a natural number n
A168327 Primes of concatenated form p= "1 n^3"
A168375 Naturals n for which the concatenation p= "1 n^3"is prime
A168487 Primes of form p = 3^3 + 10^2*n^3 with a natural number n
A168540 Naturals n for which the concatenation p = 3^3 + 10^2*n^3 is prime
Showing 1-3 of 3 results.