The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A080177

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A080177

Non-palindromic primes which on subtracting their reversal give perfect squares.
(history; published version)

#12 by Harvey P. Dale at Mon Dec 03 18:56:44 EST 2018

STATUS

editing

approved

#11 by Harvey P. Dale at Mon Dec 03 18:56:41 EST 2018

LINKS

Harvey P. Dale, <a href="/A080177/b080177.txt">Table of n, a(n) for n = 1..1000</a>

STATUS

approved

editing

#10 by Harvey P. Dale at Mon Dec 03 18:53:21 EST 2018

STATUS

editing

approved

#9 by Harvey P. Dale at Mon Dec 03 18:53:17 EST 2018

MATHEMATICA

Select[Prime[Range[13000]], !PalindromeQ[#]&&IntegerQ[Sqrt[#-IntegerReverse[ #]]]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 03 2018 *)

STATUS

approved

editing

#8 by M. F. Hasler at Wed Nov 20 08:33:26 EST 2013

STATUS

reviewed

approved

#7 by Michel Marcus at Wed Nov 20 08:17:32 EST 2013

STATUS

proposed

reviewed

Discussion

Wed Nov 20

08:33

M. F. Hasler: thx for catching the typo. lol @ source -- of entropy ?

#6 by Michel Marcus at Wed Nov 20 08:14:54 EST 2013

STATUS

editing

proposed

Discussion

Wed Nov 20

08:15

Michel Marcus: Comme on disait en taupe, voilà une source au sens thermodynamique du terme !

#5 by Michel Marcus at Wed Nov 20 08:14:09 EST 2013

LINKS

ArchimdesArchimedes' lab, Lab, <a href="http://www.archimedes-lab.org/numbers/Num24_69.html#43">What is special about this number? - 43</a>.

STATUS

proposed

editing

#4 by M. F. Hasler at Wed Nov 20 06:59:54 EST 2013

STATUS

editing

proposed

#3 by M. F. Hasler at Wed Nov 20 06:59:49 EST 2013

NAME

Non-palindromic primes which on subtracting their reversal gives give perfect squares.

COMMENTS

See A232183 for the variant including palindromic primes for which p-R(p) = 0 = 0^2.

LINKS

Archimdes' lab, <a href="http://www.archimedes-lab.org/numbers/Num24_69.html#43">What is special about this number? - 43</a>.

PROG

(PARI) forprime(p=1, 19999, issquare(p-A004086(p))&&p-A004086(p)&&print1(p", ")) \\ - M. F. Hasler, Nov 20 2013

STATUS

approved

editing