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A225684 Nonpalindromic numbers n with property that the sum of the reversed divisors of n is equal to n+1. 0

%I

%S 965,8150,12966911,625261742

%N Nonpalindromic numbers n with property that the sum of the reversed divisors of n is equal to n+1.

%C Palindromes are excluded because palindromic primes automatically have this property, and palindromic nonprimes never have it.

%C Call a number "quasi-perfect" or "slightly excessive" if sigma(n) = 2n+1 (cf. A000203). It is conjectured that no quasi-perfect number exists. The present sequence is a variation that certainly has at least four terms.

%C a(5) > 10^11. - _Donovan Johnson_, May 26 2013

%C a(5) > 10^12. - _Giovanni Resta_, Aug 19 2019

%H Jason Earls, <a href="http://voices.yahoo.com/all-reversed-slightly-excessive-numbers-1315225.html">All About Reversed Slightly Excessive Numbers</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/QuasiperfectNumber.html">Quasi-perfect number</a>

%e The divisors of 965 are 1, 5, 193, 965, and reversing and adding produces 1 + 5 + 391 + 569 = 966.

%Y Cf. A069192, A069250, A000203.

%K nonn,base,more

%O 1,1

%A _N. J. A. Sloane_, May 19 2013

%E a(4) from _Donovan Johnson_, May 19 2013

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Last modified July 12 05:35 EDT 2020. Contains 335658 sequences. (Running on oeis4.)