The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A265109 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A265109

a(n) = largest k such that prime(n) + A002110(k) is prime.
(history; published version)

#24 by Michael De Vlieger at Thu Jan 25 12:18:52 EST 2024

STATUS

proposed

approved

#23 by Andrew Howroyd at Thu Jan 25 12:11:30 EST 2024

STATUS

editing

proposed

#22 by Andrew Howroyd at Thu Jan 25 12:11:20 EST 2024

PROG

(PARI) a(n) = {my(k=1); while(k, if(ispseudoprime(prod(i=1, n-k, prime(i)) + prime(n)), return(n-k)); k++)}

STATUS

proposed

editing

#21 by Michel Marcus at Thu Jan 25 12:08:19 EST 2024

STATUS

editing

proposed

#20 by Michel Marcus at Thu Jan 25 12:08:17 EST 2024

PROG

(PARI) a(n) = {k=1; while(k, if(ispseudoprime(prod(i=1, n-k, prime(i)) + prime(n)), return(n-k)); k++)}

STATUS

approved

editing

#19 by N. J. A. Sloane at Wed Dec 02 12:21:48 EST 2015

STATUS

editing

approved

#18 by N. J. A. Sloane at Wed Dec 02 12:21:45 EST 2015

CROSSREFS

Cf. A000040, A002110, A035346, A100380.

STATUS

approved

editing

#17 by N. J. A. Sloane at Wed Dec 02 12:21:31 EST 2015

STATUS

editing

approved

#16 by N. J. A. Sloane at Wed Dec 02 12:20:46 EST 2015

NAME

Largest a(n) = largest k such that A000040prime(n) + A002110(k) is prime.

STATUS

proposed

editing

Discussion

Wed Dec 02

12:21

N. J. A. Sloane: Seems artificial, but I will approve it. Edited definition to make it less cryptic.

#15 by Altug Alkan at Wed Dec 02 11:26:18 EST 2015

STATUS

editing

proposed