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Revision History for A018068

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A018068

Powers of fourth root of 8 rounded up.
(history; published version)

#17 by Bruno Berselli at Tue Dec 29 02:51:41 EST 2020

STATUS

reviewed

approved

#16 by Joerg Arndt at Tue Dec 29 02:46:07 EST 2020

STATUS

proposed

reviewed

#15 by Kevin Ryde at Tue Dec 29 00:15:35 EST 2020

STATUS

editing

proposed

Discussion

Tue Dec 29

00:37

Michel Marcus: seems ok, but I don't understand pari syntax: an if with 4 commas

02:46

Joerg Arndt: if(cond1, cmd1, cond2, cmd2); this is an (syntactically ugly) equivalent of if(cond1) cmd1; else_if (cond2) cmd2;

#14 by Kevin Ryde at Tue Dec 29 00:13:41 EST 2020

PROG

(PARI) a(n) = n*=3; if(n%2, sqrtnint(1<<n, 4)+1, n%4, sqrtint(1<<(n/2))+1, 1<<(n/4)); \\ Kevin Ryde, Dec 29 2020

STATUS

approved

editing

Discussion

Tue Dec 29

00:15

Kevin Ryde: Pari sqrtnint I was thinking.  n mod 4 cases separated since they run much faster than giving all to sqrtnint.

#13 by Joerg Arndt at Mon Dec 28 07:15:19 EST 2020

STATUS

reviewed

approved

#12 by Michel Marcus at Mon Dec 28 04:27:10 EST 2020

STATUS

proposed

reviewed

#11 by Michel Marcus at Mon Dec 28 04:27:06 EST 2020

STATUS

editing

proposed

#10 by Michel Marcus at Mon Dec 28 04:26:51 EST 2020

PROG

(PARI) a(n) = ceil(8^(n/4)); \\ Michel Marcus, Dec 28 2020

STATUS

reviewed

editing

Discussion

Mon Dec 28

04:27

Michel Marcus: maybe next time

#9 by Joerg Arndt at Mon Dec 28 02:35:40 EST 2020

STATUS

proposed

reviewed

Discussion

Mon Dec 28

02:43

Kevin Ryde: Michel: some Pari sqrtnint(8^n,4) + (n%4 something something) could stay away from floats.  Only an exact int when n multiple of 4 ...

04:26

Michel Marcus: yes probably perhaps but I don't see the "something something" right now

#8 by Michel Marcus at Mon Dec 28 02:23:54 EST 2020

STATUS

editing

proposed