cp's OEIS Frontend

A180477 Numbers n such that r*n/k is an integer. n=(x_1 x_2 ... x_r) where x_i are digits of n, k = x_1 + x_2 + ... + x_r.

%I A180477 #7 Oct 12 2018 20:19:19
%S A180477 1,2,3,4,5,6,7,8,9,10,11,12,15,18,20,21,22,24,27,30,33,36,40,42,44,45,
%T A180477 48,50,51,54,55,60,63,66,70,72,77,80,81,84,88,90,99,100,102,108,110,
%U A180477 111,112,114,117,120,126,132
%N A180477 Numbers n such that r*n/k is an integer. n=(x_1 x_2 ... x_r) where x_i are digits of n, k = x_1 + x_2 + ... + x_r.
%C A180477 A005349 is a subsequence of this sequence.
%C A180477 n * A055642(a(n)) mod A007953(a(n)) = 0. - _Reinhard Zumkeller_, Oct 27 2015
%H A180477 Reinhard Zumkeller, <a href="/A180477/b180477.txt">Table of n, a(n) for n = 1..10000</a>
%e A180477 n=126, r=3, 3*126/(1+2+6)=42, so 126 belongs to this sequence.
%o A180477 (Haskell)
%o A180477 a180477 n = a180477_list !! (n-1)
%o A180477 a180477_list = filter (\x -> mod (x * a055642 x) (a007953 x) == 0) [1..]
%o A180477 -- _Reinhard Zumkeller_, Oct 27 2015
%Y A180477 Cf. A005349.
%Y A180477 Cf. A007953, A055642, subsequence of A263808.
%K A180477 base,easy,nonn
%O A180477 1,2
%A A180477 _Ctibor O. Zizka_, Sep 07 2010