The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A098858 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A098858

Primes p such that floor(sqrt(2)*p) is also a prime.
(history; published version)

#12 by Susanna Cuyler at Wed Sep 04 23:58:33 EDT 2019

STATUS

proposed

approved

#11 by Michel Marcus at Wed Sep 04 13:57:42 EDT 2019

STATUS

editing

proposed

Discussion

Wed Sep 04

22:39

Robert Israel: OK

#10 by Michel Marcus at Wed Sep 04 13:57:27 EDT 2019

CROSSREFS

Cf. A001951.

STATUS

proposed

editing

Discussion

Wed Sep 04

13:57

Michel Marcus: xref ok ?

#9 by Robert Israel at Wed Sep 04 13:28:31 EDT 2019

STATUS

editing

proposed

#8 by Robert Israel at Wed Sep 04 13:28:24 EDT 2019

LINKS

Robert Israel, <a href="/A098858/b098858.txt">Table of n, a(n) for n = 1..10000</a>

MAPLE

filter:= proc(p) isprime(p) and isprime(floor(sqrt(2)*p)) end proc:

select(filter, [2, seq(i, i=3..3000, 2)]); # Robert Israel, Sep 04 2019

STATUS

approved

editing

#7 by Russ Cox at Fri Mar 30 17:34:14 EDT 2012

AUTHOR

_Roger L. Bagula (rlbagulatftn(AT)yahoo.com), _, Oct 11 2004

Discussion

Fri Mar 30

17:34

OEIS Server: https://oeis.org/edit/global/158

#6 by Charles R Greathouse IV at Tue Nov 23 23:38:32 EST 2010

STATUS

proposed

approved

#5 by Charles R Greathouse IV at Tue Nov 23 23:38:29 EST 2010

NAME

Primes p such that floor(sqrt(2)*p) is also a aprimeprime.

STATUS

approved

proposed

#4 by N. J. A. Sloane at Fri Sep 29 03:00:00 EDT 2006

NAME

Primes p such that floor(sqrt(2)*p) is also primea aprime.

OFFSET

0,1,1

EXAMPLE

59 and floor(sqrt(2)*59)=83 are primes.

KEYWORD

nonn,new

nonn

#3 by N. J. A. Sloane at Fri Feb 24 03:00:00 EST 2006

MATHEMATICA

(* primes that when multiplied by Sqrt[2] give new primes*) digits=1200 a=Delete[Union[Table[If[PrimeQ[Floor[Prime[n]*Sqrt[2]]]==True, Prime[n], 0], {n, 1, digits}]], 1]

KEYWORD

nonn,new

nonn