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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.
1
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).
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
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