The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A323746 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A323746

a(n) is the smallest positive number that is as far as possible from the nearest multiple of each of the first n primes.
(history; published version)

#16 by Michel Marcus at Fri Jan 24 17:08:29 EST 2025

STATUS

reviewed

approved

#15 by Andrew Howroyd at Fri Jan 24 17:06:20 EST 2025

STATUS

proposed

reviewed

#14 by Robert C. Lyons at Fri Jan 24 16:01:30 EST 2025

STATUS

editing

proposed

#13 by Robert C. Lyons at Fri Jan 24 16:01:27 EST 2025

PROG

(PARI) \\ See Corneth link \\ _. _David A. Corneth_, May 09 2019

STATUS

approved

editing

#12 by Bruno Berselli at Thu May 09 04:53:17 EDT 2019

STATUS

proposed

approved

#11 by David A. Corneth at Thu May 09 01:56:11 EDT 2019

STATUS

editing

proposed

#10 by David A. Corneth at Thu May 09 01:52:18 EDT 2019

LINKS

David A. Corneth, <a href="/A323746/a323746.gp.txt">TITLE FOR LINKPARI program</a>

PROG

(PARI) See Corneth link \\ David A. Corneth, May 09 2019

Discussion

Thu May 09

01:56

David A. Corneth: This program computes terms individually and so doesn't use earlier terms. I imagine the implementation of this idea could be improved. It uses cutting and branching and the chinese remainder theorem but the former might be optimized, I'm not sure. Perhaps a(n-1) could help there. Anyway, this is a start. For me runtime increases slightly less than a factor 2 on average it seems.

#9 by David A. Corneth at Thu May 09 01:51:05 EDT 2019

LINKS

David A. Corneth, <a href="/A323746/a323746.gp.txt">TITLE FOR LINK</a>

STATUS

proposed

editing

#8 by Jon E. Schoenfield at Thu May 09 00:24:34 EDT 2019

STATUS

editing

proposed

#7 by Jon E. Schoenfield at Thu May 09 00:21:55 EDT 2019

PROG

(Magma) N:=21; p:=2; prod:=p; R:=[1]; a:=R; for n in [2..N] do p:=NthPrime(n); RR:=[]; u1:=p div 2; u2:=u1+1; for m in [0..p-1] do o:=m*prod; for r in R do t:=o+r; u:=t mod p; if (u eq u1) or (u eq u2) then RR[#RR+1]:=t; if n eq N then a[n]:=t; break n; end if; end if; end for; end for; R:=RR; a[n]:=R[1]; prod*:=p; end for; a;

STATUS

proposed

editing

Discussion

Thu May 09

00:24

Jon E. Schoenfield: @David -- << here are the first few terms >> -- that looks like more than a few!  :-)  Would you like to upload a program?  (The runtime required by mine roughly doubles each time the number of terms increases by 1, but it's okay for generating enough terms to fill the Data section as full as possible without exceeding 260 characters.)