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%I #7 May 13 2013 01:48:41
%S 1,10,13,23,1233,33999999999999999
%N a(n+1) is the smallest integer greater than a(n) such that the sum of the squares of its decimal digits is equal to a(n).
%e 10 --> 1^2+0^2 = 1+0 =1
%e 13 --> 1^2+3^2 = 1+9 = 10
%e 23 --> 2^2+3^2 = 4+9 =13
%e 1233 --> 1^2+2^2+3^3+3^2 = 1+4+9+9 = 23
%e 33999999999999999 = 3^2*2 + 9^2*15 = 1233
%Y Cf. A001273, A053612.
%K nonn,base
%O 1,2
%A _Paolo P. Lava_ and _Giorgio Balzarotti_, Mar 20 2007; corrected Mar 23 2007
%E Next term is greater than 10^419753086419753. [From _Charles R Greathouse IV_, Nov 13 2010]
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