A074462 Average digit (rounded up) in the decimal expansion of prime(n).

2, 3, 5, 7, 1, 2, 4, 5, 3, 6, 2, 5, 3, 4, 6, 4, 7, 4, 7, 4, 5, 8, 6, 9, 8, 1, 2, 3, 4, 2, 4, 2, 4, 5, 5, 3, 5, 4, 5, 4, 6, 4, 4, 5, 6, 7, 2, 3, 4, 5, 3, 5, 3, 3, 5, 4, 6, 4, 6, 4, 5, 5, 4, 2, 3, 4, 3, 5, 5, 6, 4, 6, 6, 5, 7, 5, 7, 7, 2, 5, 5, 3, 3, 4, 6, 4, 6, 6, 4, 5, 6, 7, 7, 5, 8, 3, 5, 3, 4, 4, 6, 6, 5, 7, 5, 7, 7, 6, 8, 3, 5, 4, 5, 6, 4, 4, 5, 6, 5, 7

Offset

1,1

Links

Table of n, a(n) for n=1..120.

Formula

a(n) = ceiling(A007605(n)/A097944(n)). - R. J. Mathar, Sep 23 2008

a(n) = A004427(A000040(n)). - Reinhard Zumkeller, May 27 2010

Example

The prime numbers begin with 2,3,5,7,11,13,17,19,23,... so the average digits rounded up are 2, 3, 5, 7, (1+1)/2=1, (1+3)/2=2, (1+7)/2=4, (1+9)/2=5, ceiling((2+3)/2)=3, ...

Mathematica

Table[Ceiling[Mean[IntegerDigits[p]]], {p, Prime[Range[120]]}] (* Harvey P. Dale, Nov 06 2022 *)

Prog

(PARI) a(n) = my(d=digits(prime(n))); ceil(vecsum(d)/#d); \\ Michel Marcus, Apr 23 2022

Crossrefs

Cf. A000040, A004427, A074461, A073342.

Cf. A007605, A097944.

Sequence in context: A074461 A285095 A073342 * A113656 A007652 A060418

Adjacent sequences: A074459 A074460 A074461 * A074463 A074464 A074465

Keyword

easy,nonn,base

Author

Y. Kelly Itakura (yitkr(AT)mta.ca), Aug 23 2002

Extensions

Offset changed to 1, cf. to A073342 added, and extended by R. J. Mathar, Sep 23 2008

Status

approved