The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A292918 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A292918

Let A_n be a square n X n matrix with entries A_n(i,j)=1 if i+j is prime, and A_n(i,j)=0 otherwise. Then a(n) counts the 1's in A_n.
(history; published version)

#50 by Peter Luschny at Sat Dec 09 09:11:39 EST 2023

STATUS

proposed

approved

#49 by Stefano Spezia at Sat Dec 09 06:38:49 EST 2023

STATUS

editing

proposed

#48 by Stefano Spezia at Sat Dec 09 06:35:32 EST 2023

LINKS

William Dowling and Nadia Lafreniere, <a href="https://arxiv.org/abs/2312.02383">Homomesy on permutations with toggling actions</a>, arXiv:2312.02383 [math.CO], 2023. See page 10.

STATUS

approved

editing

#47 by Alois P. Heinz at Mon Oct 30 10:58:42 EDT 2023

STATUS

reviewed

approved

#46 by Michel Marcus at Mon Oct 30 10:57:31 EDT 2023

STATUS

proposed

reviewed

#45 by Ridouane Oudra at Mon Oct 30 08:23:02 EDT 2023

STATUS

editing

proposed

#44 by Ridouane Oudra at Mon Oct 30 08:20:52 EDT 2023

FORMULA

a(n) = Sum_{p <= 2n+1, p prime} min(p-1, 2n+1-p). - Ridouane Oudra, Oct 30 2023

STATUS

approved

editing

#43 by Charles R Greathouse IV at Thu Sep 08 08:46:19 EDT 2022

PROG

(MAGMAMagma) sol:=[]; for n in [1..56] do k:=0; for i, j in [1..n] do if IsPrime(i+j) then k:=k+1; end if; end for; Append(~sol, k); end for; sol; // Marius A. Burtea, Aug 29 2019

Discussion

Thu Sep 08

08:46

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

#42 by Joerg Arndt at Sun May 10 02:52:29 EDT 2020

STATUS

reviewed

approved

#41 by Michel Marcus at Sun May 10 02:26:15 EDT 2020

STATUS

proposed

reviewed