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%I #12 Apr 23 2021 05:18:29
%S 9,24,27,42,60,72,78,81,105,114,126,132,150,180,186,192,195,204,216,
%T 222,231,234,243,258,276,285,315,330,336,342,348,357,366,375,378,396,
%U 402,429,438,450,465,474,480,483,492,510,540,555,558,564,576,582,585
%N 3-Suzanne numbers.
%C Composite numbers k such that the sum of digits of k (A007953) and the sum of sums of digits of the prime factors of k (taken with multiplicity, A118503) are both divisible by 3. - _Amiram Eldar_, Apr 23 2021
%D József Sándor and Borislav Crstici, Handbook of Number theory II, Kluwer Academic Publishers, 2004, Chapter 4, p. 384.
%D James J. Tattersall, Elementary Number Theory in Nine Chapters, 2nd ed., Cambridge University Press, 2005, p. 93.
%H Amiram Eldar, <a href="/A102217/b102217.txt">Table of n, a(n) for n = 1..10000</a>
%H Michael Smith, <a href="https://www.fq.math.ca/Scanned/34-2/smith.pdf">Cousins of Smith Numbers: Monica and Suzanne Sets</a>, Fibonacci Quarterly, Vol. 34, No. 2 (1996), pp. 102-104.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SuzanneSet.html">Suzanne Set</a>.
%t s[n_] := Plus @@ IntegerDigits[n]; f[p_, e_] := e*s[p]; sp[n_] := Plus @@ f @@@ FactorInteger[n]; suz3Q[n_] := CompositeQ[n] && And @@ Divisible[{s[n], sp[n]}, 3]; Select[Range[600], suz3Q] (* _Amiram Eldar_, Apr 23 2021 *)
%Y Subsequence of A177927.
%Y Cf. A007953, A018252, A102216, A118503.
%K nonn,base
%O 1,1
%A _Eric W. Weisstein_, Dec 30 2004
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