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%I #12 Jul 04 2019 14:57:12
%S 0,9,205,212,217,366,457,663,1314,1315,1348,1672,1742,1792,1797,2005,
%T 2012,2017,2129,2201,2208,2213,2216,2305,2404,2405,2465,2564,2565,
%U 2671,2741,2748,2789,2829,3114,3115,3205,3303,3306,3394,3436,3475,3696,3819,4204,4205,4245,4347,4475,4542,4629,4647,4688
%N Integers k such that if m = k + A003132(k) then k = m - A003132(m).
%C A003132(n) is the sum of the squares of the digits of n.
%e 205 is in the sequence because 205 + 2^2 + 0^2 + 5^2 = 234 and 234 - 2^2 - 3^2 - 4^2 = 205.
%t sod2[n_] := Total @ (IntegerDigits[n]^2); aQ[n_] := sod2[n + (s=sod2[n])] == s; Select[Range[0, 4700], aQ] (* _Amiram Eldar_, Jul 03 2019 *)
%o (PARI) for(i = 0 , 5000 , a = i + norml2(digits(i)) ; b = a - norml2(digits(a)) ; if(i == b , print1(i , ", ")))
%Y Cf. A003132, A108662, A175396, A209303, A223035, A225049, A258881.
%K nonn,base
%O 1,2
%A _Antonio Roldán_, Apr 25 2019
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