Your starting example is presumably a Borgnine. M On 10/04/2021 23:03, 'Nollaig MacKenzie' via Chat wrote:
Generalizing recklessly from the single example, 7 of 9, I conjectured thatborgnum n would be the greatest prime less than n^2 Looking for a J expression took me to: borgnum=:p:@(<:@(p:^:_1))@*: whence the 1st 10 borg numbers are 3 7 13 23 31 47 61 79 97 113 What was pleasing, of course, was the way p:^:_1 gave just what I wanted. I checked OEIS.org, and, indeed, the sequence is there, A053001, not, alas, identified as the borg numbers. Sent using Hushmail ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
-- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
