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A125687 The base 6 numbers 4 44 444 4444 44444 ... converted to base 10. 1
4, 28, 172, 1036, 6220, 37324, 223948, 1343692, 8062156, 48372940, 290237644, 1741425868, 10448555212, 62691331276, 376147987660, 2256887925964, 13541327555788, 81247965334732, 487487792008396, 2924926752050380, 17549560512302284, 105297363073813708 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..22.

FORMULA

a(n) = (6^n-1)*4/5.

G.f.: 4*x/((1-x)*(1-6*x)). - Vincenzo Librandi, Sep 26 2015

EXAMPLE

Base 6.........decimal

4....................4

44..................28

444................172

4444..............1036

44444.............6220

444444...........37324

4444444.........223948

44444444.......1343692

444444444......8062156

4444444444....48372940

etc.

MAPLE

seq((6^n-1)*4/5, n=1..24);

MATHEMATICA

4 (6^Range[20]-1)/5  (* Harvey P. Dale, Mar 12 2011 *)

Rest[CoefficientList[Series[4 x/((1 - x) (1 - 6 x)), {x, 0, 30}], x]] (* Vincenzo Librandi, Sep 26 2015 *)

PROG

(MAGMA) [(6^n-1)*4/5: n in [1.. 35]]; // Vincenzo Librandi, Sep 26 2015

CROSSREFS

Sequence in context: A182190 A317232 A272456 * A272791 A291918 A223166

Adjacent sequences:  A125684 A125685 A125686 * A125688 A125689 A125690

KEYWORD

easy,nonn

AUTHOR

Zerinvary Lajos, Jan 31 2007

EXTENSIONS

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

More terms from Vincenzo Librandi, Sep 26 2015

STATUS

approved

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Last modified November 12 17:06 EST 2019. Contains 329058 sequences. (Running on oeis4.)