A107295 - OEIS

A107295

Numbers k such that prime(k^2) - k^2 is prime.

2, 4, 12, 14, 20, 42, 48, 56, 60, 88, 104, 120, 126, 134, 138, 160, 164, 182, 186, 204, 226, 254, 270, 276, 312, 316, 330, 336, 350, 382, 408, 410, 414, 422, 438, 448, 450, 480, 492, 494, 502, 522, 546, 568, 580, 596, 620, 624, 640, 650, 690, 696

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..52.

EXAMPLE

88 is in the sequence because prime(88^2) - 88^2 = prime(7744) - 7744 = 78977 - 7744 = 71233 = prime(7051).

MATHEMATICA

Select[Range[700], PrimeQ[Prime[#^2]-#^2]&] (* Harvey P. Dale, Jun 20 2015 *)

PROG

(PARI) isok(n) = isprime(prime(n^2) - n^2); \\ Michel Marcus, Oct 09 2013

CROSSREFS

Cf. A064269 (prime(n)-n is prime), A141129 (prime(n^2)-n^2).

Sequence in context: A039587 A194368 A111069 * A039564 A297064 A263466

Adjacent sequences: A107292 A107293 A107294 * A107296 A107297 A107298

KEYWORD

nonn

AUTHOR

Zak Seidov, May 20 2005

EXTENSIONS

More terms from Michel Marcus, Oct 09 2013

STATUS

approved

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.