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Numbers n such that the sum of the digits of n plus the sum of the digits of n^2 is prime.
4

%I #9 Apr 17 2013 18:05:47

%S 1,4,10,28,37,40,43,58,64,73,79,82,85,91,100,109,118,124,127,139,148,

%T 154,175,181,187,208,226,229,232,235,241,247,253,265,271,277,280,286,

%U 298,304,313,316,319,322,325,331,334,349,352,355,367,370,397,400,403,415,421,424,430,433,448,454,457,469,478,481,487,505,517,526,529,532,538,544,547,571,574,577,580,586,589,598

%N Numbers n such that the sum of the digits of n plus the sum of the digits of n^2 is prime.

%H Vincenzo Librandi, <a href="/A186278/b186278.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Range[1000],PrimeQ[Total[IntegerDigits[#]]+Total[IntegerDigits[#^2]]]&]

%Y Cf. A186279.

%K nonn,easy,base

%O 1,2

%A _Harvey P. Dale_, Feb 16 2011