Problem was you were not frivolous enough! i was totally surprised when Sloane accepted https://oeis.org/A028374 https://oeis.org/A028373 They even gathered computational amendments straight facedly!
~greg https//picsrp.github.io -- from: 'Nollaig MacKenzie' <[email protected]> to: [email protected] date: Apr 23, 2021, 2:45 PM subject: Re: [Jchat] borg numbers (frivolous) >It would have been smart of me to read the docs; I would have seen that (_4 p: *:) 2+i.10 -- from: 'Nollaig MacKenzie' <[email protected]> to: [email protected] date: Apr 10, 2021, 10:28 PM subject: Re: [Jchat] borg numbers (frivolous) Nifty! -- from: Brian Schott <[email protected]> to: Chat forum <[email protected]> date: Apr 10, 2021, 5:22 PM subject: Re: [Jchat] borg numbers (frivolous) >was even more surprised by this where &. undoes an inverse. p=.(<:&.(p:^:_1))@*: p"0] 2+i. 10 3 7 13 23 31 47 61 79 97 113 (B=) -- from: greg heil <[email protected]> to: Chat forum <[email protected]> date: Apr 10, 2021, 4:09 PM subject: Re: [Jchat] borg numbers (frivolous) Speaking of the Borg i sometimes wonder if Google brain wonders why suddenly all the searches for Borgnine ~greg https//picsrp.github.io -- from: 'Michael Day' via Chat <[email protected]> to: [email protected] date: Apr 10, 2021, 3:56 PM subject: Re: [Jchat] borg numbers (frivolous) Your starting example is presumably a Borgnine. M -- from: 'Nollaig MacKenzie' [email protected] to: [email protected] date: Apr 10, 2021, 3:03 PM subject: [Jchat] borg numbers (frivolous) >Generalizing recklessly from the single example, 7 of 9, I conjectured that borgnum 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. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
