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%I #13 Sep 13 2015 07:43:20
%S 12,810,35152,18,9,67881,6,36,20,12,3,7203,14688,162,350,6,81,75,9,24,
%T 25,3648,37905,2125,3,18,455,225,27,3800,81,12,343,54,26730,1540,180,
%U 6,14,48,5,10010,96348,798,49,360,9,45,3430,192,126,36,3,225,729,648
%N a(n) is the smallest k such that the sum of squares of prime divisors of k is equal to the sum of prime divisors of n+k.
%C Smallest k such that A005063(k) = A008472(n+k), where A008472(n) is the sum of the distinct primes dividing n and A005063(n) is the sum of squares of primes dividing n.
%e a(2) = 810 because the prime divisors of 810 are {2, 3, 5}, the prime divisors of 810 + 2 = 812 are {2, 7, 29} and 2^2 + 3^2 + 5^2 = 2 + 7 + 29 = 38, hence 810 is in the sequence.
%t sk[n_]:=Module[{k=1},While[Plus@@(First@#&/@FactorInteger[k]^2)!=Plus@@(First@#&/@FactorInteger[n+k]),k++];k];Array[sk,65,1]
%Y Cf. A005063, A008472, A228181.
%K nonn
%O 1,1
%A _Michel Lagneau_, Aug 15 2013
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