cp's OEIS Frontend

A004427 Arithmetic mean of digits of n (rounded up).

%I A004427 #25 Jun 08 2019 01:09:53
%S A004427 0,1,2,3,4,5,6,7,8,9,1,1,2,2,3,3,4,4,5,5,1,2,2,3,3,4,4,5,5,6,2,2,3,3,
%T A004427 4,4,5,5,6,6,2,3,3,4,4,5,5,6,6,7,3,3,4,4,5,5,6,6,7,7,3,4,4,5,5,6,6,7,
%U A004427 7,8,4,4,5,5,6,6,7,7,8,8,4,5,5,6,6,7,7,8,8,9,5,5,6,6,7,7,8,8,9,9,1,1,1,2,2,2,3,3
%N A004427 Arithmetic mean of digits of n (rounded up).
%C A004427 a(100)=1 is the first value that differs from the variant "... rounded to the nearest integer". - _M. F. Hasler_, May 10 2015
%H A004427 R. Zumkeller, <a href="/A004427/b004427.txt">Table of n, a(n) for n = 0..25000</a>
%H A004427 <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a>
%F A004427 From _Reinhard Zumkeller_, May 27 2010: (Start)
%F A004427 a(n) = ceiling(A007953(n)/A055642(n)); a(A000040(n)) = A074462(n);
%F A004427 A004426(n) <= a(n) with equality for n in A061383;
%F A004427 a(A178361(n)) = 1; a(A178362(n)) = 2; a(A178363(n)) = 3; a(A178364(n)) = 4; a(A178365(n)) = 5; a(A178366(n)) = 6; a(A178367(n)) = 7; a(A178368(n)) = 8; a(A178369(n)) = 9. (End)
%t A004427 Ceiling[Mean[IntegerDigits[#]]]&/@Range[0,110] (* _Harvey P. Dale_, Aug 29 2014 *)
%o A004427 (PARI) A004427(n)=ceil(sum(i=1, #n=digits(n), n[i])/#n) \\ ...Vecsmall(Str(n))...-48 is a little faster. \\ _M. F. Hasler_, May 10 2015
%Y A004427 Cf. A178358, A178359, A178361, A178362, ..., A178369, A178401, A178402, A178403, A178404, A178405.
%Y A004427 Cf. A000040, A004426, A007953, A055642, A061383, A074462.
%K A004427 nonn,base
%O A004427 0,3
%A A004427 _N. J. A. Sloane_