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A125682 a(n) = (6^n-1)*3/5. 2
3, 21, 129, 777, 4665, 27993, 167961, 1007769, 6046617, 36279705, 217678233, 1306069401, 7836416409, 47018498457, 282110990745, 1692665944473, 10155995666841, 60935974001049, 365615844006297, 2193695064037785, 13162170384226713, 78973022305360281 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The base 6 numbers 3, 33, 333, 3333, 33333, 333333, ... converted to base 10.

LINKS

Bruno Berselli, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (7,-6).

FORMULA

G.f.: 3*x/((1-x)*(1-6*x)). [Bruno Berselli, Apr 18 2012]

EXAMPLE

Base 6        Base 10

3 ............. 3 = 3*6^0

33 ........... 21 = 3*6^1+3*6^0

333 ......... 129 = 3*6^2+3*6^1+3*6^0

3333 ........ 777 = 3*6^3+3*6^2+3*6^1+3*6^0, etc.

MAPLE

seq((6^n-1)*3/5, n=1..27);

PROG

(MAGMA) [(6^n-1)*3/5: n in [1..22]]; // Bruno Berselli, Apr 18 2012

CROSSREFS

Cf. A003464, A005610, A125687, A024062, A105281, A146884.

Sequence in context: A273803 A036754 A121447 * A125701 A274586 A124812

Adjacent sequences:  A125679 A125680 A125681 * A125683 A125684 A125685

KEYWORD

nonn,easy

AUTHOR

Zerinvary Lajos, Jan 31 2007

EXTENSIONS

Edited by N. J. A. Sloane, Feb 02 2007

Definition rewritten (with Lajos formula) from Bruno Berselli, Apr 18 2012

STATUS

approved

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Last modified October 22 10:24 EDT 2019. Contains 328317 sequences. (Running on oeis4.)