A004427 - OEIS

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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

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OFFSET

0,3

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

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)

MATHEMATICA

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

PROG

(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

CROSSREFS

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

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

Sequence in context: A134777 A253015 A257295 * A113230 A065881 A133048

Adjacent sequences: A004424 A004425 A004426 * A004428 A004429 A004430

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane

STATUS

approved