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%I #54 Jul 23 2019 21:10:50
%S 4,6,8,9,1,3,5,6,7,9,2,3,4,6,7,8,9,10,3,5,6,7,8,9,11,12,4,6,8,9,10,12,
%T 13,5,6,7,9,10,11,12,13,6,8,9,10,11,12,14,15,7,9,11,12,13,14,15,8,9,
%U 10,12,13,14,15,16,9,10,11,12,13,14,15,17,18,1,3,5
%N Digital sum of composite numbers.
%F a(n) = A007953(A002808(n)).
%e The 6th term is 3 because the digital sum of 12 (the 6th composite number) is 3 (1+2).
%t Total /@ IntegerDigits /@ Select[Range[104], CompositeQ] (* _Giovanni Resta_, May 28 2019 *)
%o (PARI) lista(nn) = forcomposite(n=1, nn, print1(sumdigits(n), ", ")); \\ _Michel Marcus_, May 28 2019
%Y Cf. A002808 (composite numbers), A007953 (sum of digits).
%Y Cf. A007605 (sum of digits of primes).
%K nonn,easy,base
%O 1,1
%A _Kei Ryan_, May 27 2019
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