OFFSET
1,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
MATHEMATICA
idnQ[n_]:=Total[1/Select[IntegerDigits[n], #>0&]]==1; Select[Range[ 4000], idnQ] (* Harvey P. Dale, Dec 08 2012 *)
PROG
(Haskell)
import Data.Ratio ((%), numerator, denominator)
a214959 n = a214959_list !! (n-1)
a214959_list = [x | x <- [0..], f x 0] where
f 0 v = numerator v == 1 && denominator v == 1
f u v | d > 0 = f u' (v + 1 % d)
| otherwise = f u' v where (u', d) = divMod u 10
(Magma) SumReciprocalsDigits:=func<n | &+[1/d: d in Intseq(n) | not IsZero(d)]>; [n: n in [1..3636] | IsOne(SumReciprocalsDigits(n))]; // Bruno Berselli, Aug 02 2012
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Aug 02 2012
STATUS
approved