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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A211873 Numbers b >= 0 such that 2 b^2 + 3 b + 5 is prime.

Original entry on oeis.org

0, 2, 8, 14, 22, 24, 28, 42, 52, 58, 62, 64, 72, 84, 92, 94, 98, 114, 122, 134, 142, 148, 168, 178, 188, 202, 212, 218, 244, 248, 262, 274, 282, 302, 304, 308, 314, 318, 324, 328, 338, 342, 352, 358, 364, 372, 374, 392, 394, 398, 402, 408, 414, 434, 442, 448, 478, 484, 492, 498
Offset: 1

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Author

M. F. Hasler, Mar 31 2013

Keywords

Comments

An example of Sun's conjecture in A217788: For a(n)>5, also bases b such [2;3;5] seen as a number written in base b, is prime.

Crossrefs

Cf. A224217.

Programs

  • Magma
    [b: b in [0..500] | IsPrime(2*b^2+3*b+5)]; // Bruno Berselli, Apr 11 2013
  • PARI
    n=#v=[2,3,5];for(b=0,500,ispseudoprime(sum(k=1,n,b^(n-k)*v[k]))&print1(b","))
    
Showing 1-1 of 1 results.