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 31-32 of 32 results.

A182351 Primes of the form n^4 - 6.

Original entry on oeis.org

619, 1500619, 577200619, 3603000619, 4931550619, 12594450619, 24343800619, 29661450619, 32625390619, 65037750619, 88223850619, 195562950619, 220172100619, 586181640619, 1335469140619, 1659523650619, 2480703750619
Offset: 1

Views

Author

Patrick Devlin, Apr 25 2012

Keywords

Examples

			619 = 5^4 - 6; 1500619 = 35^4 - 6.
		

Crossrefs

Cf. A037896.

Programs

  • Maple
    # choose N large, then S is the desired set
    f:=n->n^4 - 6:
    S:={}:
    for n from 0 to N do if(isprime(f(n))) then S:=S union {f(n)}: fi: od:
  • Mathematica
    Select[Range[3,3001,2]^4-6,PrimeQ] (* Harvey P. Dale, Mar 03 2023 *)

A309844 Primes of the form n^4 + n^2 + 3.

Original entry on oeis.org

3, 5, 23, 653, 10103, 83813, 160403, 234743, 280373, 1049603, 3420653, 6252503, 11319863, 52207853, 92246423, 146422103, 174913853, 221548343, 442071653, 479807123, 577224653, 607597853, 655385603, 937921253, 1222865933, 1249233683, 1387525253, 1506177293
Offset: 1

Views

Author

Christopher R. Madan, Aug 19 2019

Keywords

Comments

Digital root of all values > 3 is 5, compare A017221.

Crossrefs

Subset of A027753. Subset of A017221.

Programs

  • MATLAB
    a = [];
    for n = 0:1e3
        x = n.^4+n.^2+3;
        if isprime(x); a = [a,x]; end;
    end
    
  • Mathematica
    f[n_] := n^4 + n^2 + 3; Select[f /@ Range[0, 200], PrimeQ] (* Amiram Eldar, Aug 24 2019 *)
  • Python
    from sympy import isprime
    a = []
    for n in range(0,1000):
        x = n**4+n**2+3
        if isprime(x):
            a.append(x)
Previous Showing 31-32 of 32 results.