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Revision History for A156851

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

Primes p=prime(k) such that the largest digit of k is odd and is equal to the largest digit of p.
(history; published version)

#15 by Alois P. Heinz at Tue Jan 22 08:19:17 EST 2019

STATUS

proposed

approved

#14 by David A. Corneth at Tue Jan 22 04:10:17 EST 2019

STATUS

editing

proposed

Discussion

Tue Jan 22

04:13

Jon E. Schoenfield: It's equivalent unless I messed up.  (Insomnia and all...)  :-/

But it occurs to me that -- in the alternative I posted in the pink-box comment at 04:00 -- there's no reason to name "k"; i.e., a better alternative than the one I offered at 04:00 would be "Primes p such that the largest digit of primepi(p) is odd and is equal to the largest digit of p."

(Unless I'm really confused, which is entirely possible.)  ?:-/

04:19

David A. Corneth: If they're not equivalent we both messed up ;) last name you suggest works as well, very nice!

04:26

Jon E. Schoenfield: Thanks!  Do you prefer it over the one in the latest revision?

I think I'm finally getting sleepy (I hope) so am now calling it quitzzzzzzzzzZZZ...

06:41

David A. Corneth: Shall we leave it as is? I like that one most. Anyway, hope you got some rest!

08:19

Alois P. Heinz: thanks!

#13 by David A. Corneth at Tue Jan 22 04:09:18 EST 2019

PROG

(PARI) is(n) = vp = vecmax(digits(n)); if(vp % 2 == 0, return(0)); vpp = vecmax(digits(primepi(n))); vp == vpp \\ David A. Corneth, Jan 22 2019

STATUS

proposed

editing

Discussion

Tue Jan 22

04:10

David A. Corneth: Name as is matches data. Your alternative is equivalent right?

#12 by Jon E. Schoenfield at Tue Jan 22 04:00:27 EST 2019

STATUS

editing

proposed

#11 by Jon E. Schoenfield at Tue Jan 22 03:57:39 EST 2019

NAME

Primes p =prime(k) such that the largest odd digit of p equals k is odd and is equal to the largest odd digit of the p-th prime.

EXTENSIONS

Name corrected by Jon E. Schoenfield, Jan 22 2019

STATUS

proposed

editing

Discussion

Tue Jan 22

03:58

Jon E. Schoenfield: I had to go to the code to figure it out.  I NEVER would've gotten this meaning from the published Name.

04:00

Jon E. Schoenfield: Could someone verify that the edited Name matches the Data?

Would "Primes p such that the largest digit of k=primepi(p) is odd and is equal to the largest digit of p." be any better as a Name?

#10 by Joerg Arndt at Tue Jan 22 03:41:20 EST 2019

STATUS

editing

proposed

#9 by Joerg Arndt at Tue Jan 22 03:40:23 EST 2019

MAPLE

A054055 := proc(n) max(op(convert(n, base, 10))) ; end: for n from 1 to 400 do ldn := A054055(n) ; if type(ldn, odd) then p := ithprime(n) ; ldp := A054055(p) ; if ldp = ldn then printf("%d, ", p) ; fi; fi; od: # R. J. Mathar, Feb 20 2009

A054055 := proc(n) max(op(convert(n, base, 10))) ; end:

for n from 1 to 400 do

ldn := A054055(n) ;

if type(ldn, odd) then

p := ithprime(n) ;

ldp := A054055(p) ;

if ldp = ldn then

printf("%d, ", p) ;

fi;

fi;

od: # R. J. Mathar, Feb 20 2009

#8 by Joerg Arndt at Tue Jan 22 03:35:41 EST 2019

NAME

Primes p such that the largest odd digit odd of p = equals the largest odd digit odd of the p-th prime.

STATUS

proposed

editing

Discussion

Tue Jan 22

03:39

Joerg Arndt: Problem: prime(17) = 59 with lod(59) = 9 > lod(17) = 7.

#7 by Michel Marcus at Tue Jan 22 03:29:11 EST 2019

STATUS

editing

proposed

#6 by Michel Marcus at Tue Jan 22 03:28:25 EST 2019

CROSSREFS

Cf. A000040, A054055.

STATUS

proposed

editing

Discussion

Tue Jan 22

03:29

Michel Marcus: ?