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A214950 Denominator of sum of reciprocals of all nonzero digits of n in decimal representation.

%I A214950 #19 Jan 26 2022 12:39:22
%S A214950 1,1,2,3,4,5,6,7,8,9,1,1,2,3,4,5,6,7,8,9,2,2,1,6,4,10,3,14,8,18,3,3,6,
%T A214950 3,12,15,2,21,24,9,4,4,4,12,2,20,12,28,8,36,5,5,10,15,20,5,30,35,40,
%U A214950 45,6,6,3,2,12,30,3,42,24,18,7,7,14,21,28,35,42
%N A214950 Denominator of sum of reciprocals of all nonzero digits of n in decimal representation.
%H A214950 Reinhard Zumkeller, <a href="/A214950/b214950.txt">Table of n, a(n) for n = 0..10000</a>
%F A214950 a(A034708(n)) = a(A037268(n)) = a(A214957(n)) = a(A214959(n)) = 1;
%F A214950 a(n) = a(A004719(n)).
%t A214950 dsr[n_] := Denominator[Total[1/Select[IntegerDigits[n], # > 0 &]]]; dsr /@ Range[0, 76] (* _Jayanta Basu_, Jul 13 2013 *)
%o A214950 (Haskell)
%o A214950 import Data.Ratio ((%), denominator)
%o A214950 a214950 = f 0 where
%o A214950    f y 0 = denominator y
%o A214950    f y x = f (y + if d == 0 then 0 else 1 % d) x'
%o A214950            where (x',d) = divMod x 10
%o A214950 (PARI) a(n) = my(d=digits(n)); denominator(sum(k=1, #d, if (d[k], 1/d[k]))); \\ _Michel Marcus_, Jan 26 2022
%Y A214950 Cf. A034708, A037268, A214957, A214959, A004719.
%Y A214950 Cf. A214949 (numerators).
%K A214950 nonn,base,frac
%O A214950 0,3
%A A214950 _Reinhard Zumkeller_, Aug 02 2012