The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A056908

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A056908

Numbers k such that 36*k^2 + 36*k + 13 is prime.
(history; published version)

#19 by Hugo Pfoertner at Thu Aug 15 06:21:42 EDT 2024

STATUS

reviewed

approved

#18 by Joerg Arndt at Thu Aug 15 06:18:34 EDT 2024

STATUS

proposed

reviewed

#17 by Jason Yuen at Thu Aug 15 04:25:10 EDT 2024

STATUS

editing

proposed

#16 by Jason Yuen at Thu Aug 15 04:25:07 EDT 2024

MATHEMATICA

Select[Range[0, 700], PrimeQ[36#^2+36#+13]&] (* Vincenzo Librandi, Jul 14 2012 *)

STATUS

approved

editing

#15 by Charles R Greathouse IV at Thu Sep 08 08:45:01 EDT 2022

PROG

(MAGMAMagma) [n: n in [0..70]| IsPrime(36*n^2+36*n+13)]; // Vincenzo Librandi, Jul 14 2012

Discussion

Thu Sep 08

08:45

OEIS Server: https://oeis.org/edit/global/2944

#14 by Sean A. Irvine at Sat May 25 22:13:37 EDT 2019

STATUS

proposed

approved

#13 by Jon E. Schoenfield at Sat May 25 18:35:34 EDT 2019

STATUS

editing

proposed

#12 by Jon E. Schoenfield at Sat May 25 18:35:31 EDT 2019

NAME

Numbers n k such that 36n36*k^2 +36n 36*k + 13 is prime.

COMMENTS

36n36*k^2 +36n 36*k + 13 = (6n6*k+3)^2 + 4 , which is 4 more than a square.

EXAMPLE

a(2)=4 since 36*4^2 + 36*4 + 13 = 733 , which is prime (as well as being four more than a square).

CROSSREFS

This sequence and formula, together with A056907 and its formula, generate all primes of the form k^2+4, i.e. , A005473.

STATUS

approved

editing

#11 by Charles R Greathouse IV at Wed Mar 01 17:21:01 EST 2017

STATUS

editing

approved

#10 by Charles R Greathouse IV at Wed Mar 01 17:20:58 EST 2017

PROG

(PARI) is(n)=isprime(36*n^2+36*n+13) \\ Charles R Greathouse IV, Mar 01 2017

STATUS

approved

editing