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

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, 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, 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

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• base

Comments

a(100)=1 is the first value that differs from the variant "... rounded to the nearest integer". - M. F. Hasler, May 10 2015

Links

• R. Zumkeller, Table of n, a(n) for n = 0..25000
• Index entries for Colombian or self numbers and related sequences

Crossrefs

Cf. A178358, A178359, A178361, A178362, ..., A178369, A178401, A178402, A178403, A178404, A178405.

Cf. A000040, A004426, A007953, A055642, A061383, A074462.

Programs

Mathematica

Ceiling[Mean[IntegerDigits[#]]]&/@Range[0,110] (* Harvey P. Dale, Aug 29 2014 *)

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

Formula

From Reinhard Zumkeller, May 27 2010: (Start)

a(n) = ceiling(A007953(n)/A055642(n)); a(A000040(n)) = A074462(n);

A004426(n) <= a(n) with equality for n in A061383;

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)