A135319 a(n) is the first digit after the decimal point in the decimal expansion of log_10(n), i.e., of the Briggsian logarithm of n.

0, 3, 4, 6, 6, 7, 8, 9, 9, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9

Offset

1,2

References

Erwin Voellmy, Fünfstellige Logarithmen und Zahlentafeln, 15th edition, Orell Foessli Verlag, Zurich (1962).

Links

Table of n, a(n) for n=1..99.

Wikipedia, Common logarithm

Formula

a(n) = floor(10*(log_10(n) - floor(log_10(n)))).

Example

a(6) = 7, because log_10(6) = 0.77815...

Maple

A135319 := proc(n) floor(10*log[10](n)) mod 10 ; end: seq(A135319(n), n=1..80) ; # R. J. Mathar, Jan 11 2008

Crossrefs

Sequence in context: A217032 A300305 A160095 * A329193 A004219 A077542

Adjacent sequences: A135316 A135317 A135318 * A135320 A135321 A135322

Keyword

base,easy,nonn

Author

Pahikkala Jussi, Dec 06 2007, Jan 13 2008

Extensions

More terms from R. J. Mathar and N. J. A. Sloane, Jan 11 2008

Status

approved