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 1-2 of 2 results.

A155702 Primes of the form 2n^2-9.

Original entry on oeis.org

23, 41, 89, 191, 233, 383, 503, 569, 1049, 1559, 1913, 2039, 2441, 2729, 2879, 3191, 3863, 4409, 4793, 5399, 6263, 6719, 7433, 8969, 9239, 9791, 12473, 12791, 14783, 16553, 18041, 19991, 20393, 23753, 26903, 29759, 33791, 34313, 37529, 39191, 46199
Offset: 1

Views

Author

Vincenzo Librandi, Jan 25 2009

Keywords

Comments

Equivalently, primes of the form 2n^2+16n+23.

Crossrefs

Programs

  • Magma
    [a: n in [2..300] | IsPrime(a) where a is 2*n^2-9];
  • Mathematica
    Select[Table[2n^2-9,{n,2,800}],PrimeQ]

Extensions

Definition rewritten by Bruno Berselli, Dec 04 2011

A155703 Primes p such that 2*p^2 + 16*p + 23 is also prime.

Original entry on oeis.org

3, 7, 13, 19, 31, 43, 97, 127, 223, 241, 271, 283, 307, 397, 421, 439, 577, 601, 619, 661, 673, 691, 727, 853, 859, 967, 1009, 1051, 1063, 1123, 1153, 1237, 1321, 1429, 1447, 1543, 1567, 1597, 1609, 1657, 1669, 1861, 1867, 1933, 1951, 1987, 2017, 2089, 2203
Offset: 1

Views

Author

Vincenzo Librandi, Jan 25 2009

Keywords

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(3000)|IsPrime(2*p^2+16*p+23)];
  • Mathematica
    Select[Prime[Range[2500]], PrimeQ[(2*#^2 + 16*# + 23)]&] (* Vincenzo Librandi, Oct 30 2012 *)

Extensions

Entries confirmed by John W. Layman, Jun 17 2010
Showing 1-2 of 2 results.