The On-Line Encyclopedia of Integer Sequences (OEIS)

Revisions by Ralf Stephan (See also Ralf Stephan's wiki page
and changes approved by Ralf Stephan)

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

A375071

Smallest k such that Product_{i=1..k} (n+i) divides Product_{i=1..k} (n+k+i), or 0 if there is no such k.
(history; published version)

#29 by Ralf Stephan at Thu Aug 01 02:41:38 EDT 2024

STATUS

editing

proposed

#22 by Ralf Stephan at Tue Jul 30 12:32:17 EDT 2024

STATUS

editing

proposed

#21 by Ralf Stephan at Tue Jul 30 12:31:42 EDT 2024

PROG

(PARI) a(n) =for my(k=1, 10000, if); while(prod(i=1, k, n+k+i)%prod(i=1, k, n+i)==0, return(, k))++); k;

STATUS

proposed

editing

Discussion

Tue Jul 30

12:32

Ralf Stephan: Thanks!

#20 by Ralf Stephan at Tue Jul 30 12:13:32 EDT 2024

STATUS

editing

proposed

Discussion

Tue Jul 30

12:25

Michel Marcus: rather ?  a(n) = my(k=1); while(prod(i=1, k, n+k+i)%prod(i=1, k, n+i), k++); k;

#18 by Ralf Stephan at Tue Jul 30 10:44:13 EDT 2024

DATA

1, 5, 4, 207, 206, 2475, 984, 8171, 8170, 45144, 45143

OFFSET

1,1

0,2

#17 by Ralf Stephan at Tue Jul 30 10:36:15 EDT 2024

PROG

(PARI) a(n)=for(n=3, 10, for(k=1, 10000, if(prod(i=1, k, n+k+i)%prod(i=1, k, n+i)==0, return(k))))

STATUS

proposed

editing

#16 by Ralf Stephan at Tue Jul 30 10:34:11 EDT 2024

STATUS

editing

proposed

Discussion

Tue Jul 30

10:35

Ralf Stephan: There is also the request to start with 1,5,... so hold on.

#15 by Ralf Stephan at Tue Jul 30 10:33:57 EDT 2024

PROG

(PARI) a(n)=for(n=3, 10, for(k=1, 10000, if(prod(i=1, k, n+k+i)%prod(i=1, k, n+i)==0, printreturn(n, " ", k); break)))

STATUS

proposed

editing

#14 by Ralf Stephan at Tue Jul 30 09:28:34 EDT 2024

STATUS

editing

proposed

Discussion

Tue Jul 30

10:27

Michel Marcus: I think pari code should rather be a(n) = for(k=1, 10000, if(prod(i=1, k, n+k+i) % prod(i=1, k, n+i)==0, return(k)));

#13 by Ralf Stephan at Tue Jul 30 09:28:00 EDT 2024

DATA

5, 4, 207, 206, 2475, 984, 8171, 8170, 45144, 45143

COMMENTS

a(10) = 45143 found by Bhavik Mechta, 2024.

STATUS

proposed

editing