A154511 Primes of the form 648*k^2 - 72*k + 1.

577, 31249, 40897, 64081, 77617, 126001, 186049, 208657, 581041, 982801, 1367857, 1616401, 2101249, 2567377, 3836449, 4038481, 4141441, 4566241, 4898449, 5359537, 7691041, 8413201, 8711137, 10941841, 12152449, 13240657, 14183137, 15356881, 15557041, 15758497, 16994449

Offset

1,1

Comments

The primes occur at n = 1, 7, 8, 10, 11, 14, 17, 18, 30, 39, 46, 50, 57,..

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mathematica

lst={}; Do[p=648*n^2-72*n+1; If[PrimeQ[p], AppendTo[lst, p]], {n, 0, 5*5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jan 27 2009 *)
Select[Table[648n^2-72n+1, {n, 0, 6001}], PrimeQ] (* Vincenzo Librandi, Jul 23 2012 *)

Prog

(Magma) [a: n in [0..200] | IsPrime(a) where a is 648*n^2-72*n+1]; // Vincenzo Librandi, Jul 23 2012
(PARI) select(isprime, vector(6002, n, 648*(n-1)^2 - 72*(n-1) + 1)) \\ Robert C. Lyons, Feb 27 2025

Crossrefs

Cf. A154510.

Sequence in context: A202011 A157264 A201046 * A221331 A163042 A069365

Adjacent sequences: A154508 A154509 A154510 * A154512 A154513 A154514

Keyword

nonn,easy

Author

Vincenzo Librandi, Jan 11 2009

Extensions

Incorrect formula replaced with a comment by R. J. Mathar, Jul 06 2010

Status

approved