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A059755 Odd rare numbers: odd n such that n-r and n+r are squares, where r is the reverse of n. 2


%S 65,868591084757,6979302951885,6157577986646405,8052956026592517,

%T 8052956206592517,8650327689541457,8650349867341457,

%U 619431353040136925,619631153042134925,631688638047992345,633288858025996145,633488632647994145,653488856225994125

%N Odd rare numbers: odd n such that n-r and n+r are squares, where r is the reverse of n.

%C There are 20 terms up to 10^22. - _Shyam Sunder Gupta_, Dec 14 2019

%D Shyam Sunder Gupta, "Systematic computations of rare numbers", The Mathematics Education, Vol. XXXII, No. 3, 1998.

%H Shyam Sunder Gupta, <a href="/A059755/b059755.txt">Table of n, a(n) for n = 1..20</a>

%H C. Rivera, <a href="http://www.primepuzzles.net/conjectures/conj_023.htm">Prime Puzzles Page</a>

%H Shyam Sunder Gupta, <a href="http://www.shyamsundergupta.com/rare.htm">Rare Numbers</a>

%e 65-56 = 9 and 65 + 56 = 121 are both (perfect) squares.

%Y Cf. A035519.

%K nice,nonn,base

%O 1,1

%A _Shyam Sunder Gupta_, Feb 11 2001

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Last modified November 29 19:26 EST 2020. Contains 338769 sequences. (Running on oeis4.)