A214958 Numbers for which the sum of reciprocals of nonzero digits is reciprocal of an integer.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 22, 30, 36, 40, 44, 50, 60, 63, 66, 70, 80, 88, 90, 100, 200, 202, 220, 236, 244, 263, 300, 306, 326, 333, 360, 362, 400, 404, 424, 440, 442, 488, 500, 600, 603, 606, 623, 630, 632, 660, 666, 700, 800, 808, 848, 880, 884

Offset: 1

Author

Reinhard Zumkeller, Aug 02 2012

Keywords

• nonn
• base

Comments

A214949(a(n)) = 1.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A037264 (subsequence).

Programs

Haskell

a214958 n = a214958_list !! (n-1)
a214958_list = [x | x <- [0..], a214949 x == 1]

Mathematica

nsrQ[n_] := Numerator[Total[1/Select[IntegerDigits[n], # > 0 &]]] == 1; Select[Range[884], nsrQ] (* Jayanta Basu, Jul 13 2013 *)