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A158333
Position of number of digits increment in the sequence of powers of 3.
2
1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 133, 135
OFFSET
0,2
FORMULA
a(n)=1+Floor(n/Log_10(3)) = 1+A054965(n).
EXAMPLE
For n=1 a(1)=3 since the sequence of powers of 3 is 1, 3, 9, 27, 81, 243, 729 and numbers of digits increase at position 1,3,5,...
MAPLE
A158333 := proc(n)
1+floor(n/log10(3)) ;
end proc:
seq(A158333(n), n=0..20) ; # R. J. Mathar, Sep 01 2014
MATHEMATICA
a[x_] := 1 + Floor[x/Log[10, 3]]; Table[a[i], {i, 0, 20}]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
Indices in offset, example, and formula adjusted by R. J. Mathar, May 21 2009
More terms from Robert G. Wilson v, May 29 2009
STATUS
approved