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.

A027867 Primes of the form n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2 + (n+5)^2.

Original entry on oeis.org

139, 199, 271, 811, 1279, 1459, 2539, 2791, 3331, 3919, 4231, 7159, 8011, 9859, 15319, 17191, 17839, 20551, 24979, 25759, 41851, 42859, 48079, 58231, 59419, 65539, 68071, 74611, 88591, 102199, 125299, 132331, 143239, 154579, 156511, 166351, 170371, 172399, 243631, 276079, 281251, 289099, 294391
Offset: 1

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Comments

Primes of form 55 + 30n + 6n^2. - Zak Seidov, May 20 2014
All terms == 1 or 19 (mod 30). - Robert Israel, Jul 18 2017

Crossrefs

Cf. A027866.

Programs

  • Maple
    select(isprime, [seq(6*t^2-30*t+55, t=6..1000)]); # Robert Israel, Jul 18 2017
  • Mathematica
    lst={};Do[a=n^2+(n+1)^2+(n+2)^2+(n+3)^2+(n+4)^2+(n+5)^2;If[PrimeQ[a],AppendTo[lst,a]],{n,8!}];lst (* Vladimir Joseph Stephan Orlovsky, Jun 02 2009 *)
    Select[Table[Total[(n+Range[0,5])^2],{n,200}],PrimeQ] (* Harvey P. Dale, Jul 18 2011 *)
    Select[Total/@Partition[Range[300]^2,6,1],PrimeQ] (* Harvey P. Dale, Jul 23 2021 *)

Formula

a(n) = 55 + 30*m + 6*m^2 where m = A027866(n). - Zak Seidov, May 20 2014

Extensions

More terms from Robert Israel, Jul 18 2017