Largest known probable prime Lucas Cofactors  (proper divisor of a Lucas number with a prime index)

 Cofactor

 Digits

 When

 V(277273)/11090921

 57940  

 11/2005  

 V(145703)/179214691

 30442

 10/2005

 V(145193)/38621339

 30336

 10/2005

 V(116593)/120790349

 24359

 06/2005

 V(91873)/(3674921 . 193484539 . 167745030829)    

 19175

 06/2005

 V(80761)/(23259169 . 24510801979)

 16861

 06/2005

 V(77417)/(1848717961 . 169842833791)

 16159

 06/2005

 V(68213)/(73397189 . 99325358579)

 14237

 06/2005

 V(51349)/(2156659 . 71375111 . 1457900809)

 10708

 06/2005

 V(49391)/(220185079 . 1355289041)

 10305

 06/2005

 V(45953)/(275719 . 16543081)

 9591

 09/2004

 V(43987)/175949

 9188

 09/2004

 V(39769)/(2863369 . 6334883549)

 8295

 09/2004


All 13 probable prime cofactors have passed a Miller-Rabin primality test in 10 randomly chosen bases (ispseudoprime test in PARI/GP). The 10 largest probable prime cofactors on this page are listed on Henri Lifchitz's Top 10000 PRPs page. Click here to view. All probable prime cofactors on this page were found by me except V(145703)/179214691 and V(145193)/38621339 were found by Jens Kruse Andersen.


Fibonacci and Lucas Factorizations
20 largest known prime Lucas cofactors (The Prime Pages)
Biography of Édouard Lucas
Main page


Last updated on January 31, 2012
Donovan Johnson