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A214950
Denominator of sum of reciprocals of all nonzero digits of n in decimal representation.
6
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, 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, 45, 6, 6, 3, 2, 12, 30, 3, 42, 24, 18, 7, 7, 14, 21, 28, 35, 42
OFFSET
0,3
LINKS
FORMULA
a(A034708(n)) = a(A037268(n)) = a(A214957(n)) = a(A214959(n)) = 1;
a(n) = a(A004719(n)).
MATHEMATICA
dsr[n_] := Denominator[Total[1/Select[IntegerDigits[n], # > 0 &]]]; dsr /@ Range[0, 76] (* Jayanta Basu, Jul 13 2013 *)
PROG
(Haskell)
import Data.Ratio ((%), denominator)
a214950 = f 0 where
f y 0 = denominator y
f y x = f (y + if d == 0 then 0 else 1 % d) x'
where (x', d) = divMod x 10
(PARI) a(n) = my(d=digits(n)); denominator(sum(k=1, #d, if (d[k], 1/d[k]))); \\ Michel Marcus, Jan 26 2022
CROSSREFS
Cf. A214949 (numerators).
Sequence in context: A113230 A065881 A133048 * A373064 A054055 A067456
KEYWORD
nonn,base,frac
AUTHOR
Reinhard Zumkeller, Aug 02 2012
STATUS
approved