A158333 Position of number of digits increment in the sequence of powers of 3.

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

Links

Table of n, a(n) for n=0..64.

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

A123384

Sequence in context: A033037 A246413 A246411 * A293167 A357377 A062505

Adjacent sequences: A158330 A158331 A158332 * A158334 A158335 A158336

Keyword

nonn,base

Author

Julio Cesar de la Yncera, Mar 16 2009

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