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A125823 Numbers whose base 7 representation is 4444....4. 0
0, 4, 32, 228, 1600, 11204, 78432, 549028, 3843200, 26902404, 188316832, 1318217828, 9227524800, 64592673604, 452148715232, 3165041006628, 22155287046400, 155087009324804, 1085609065273632, 7599263456915428 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

FORMULA

a(n)=4*(7^(n-1)-1)/6.

a(n)=7*a(n-1)+4 (with a(1)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Sep 30 2010]

EXAMPLE

Base 7.................decimal

0.........................0

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

44.......................32

444.....................228

4444...................1600

44444.................11204

444444................78432

4444444..............549028

44444444............3843200

etc....................etc...

MAPLE

seq(4*(7^n-1)/6, n=0..21);

CROSSREFS

Sequence in context: A098981 A120917 A099269 * A033515 A147551 A007278

Adjacent sequences:  A125820 A125821 A125822 * A125824 A125825 A125826

KEYWORD

easy,nonn

AUTHOR

Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Feb 03 2007

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Last modified February 14 23:53 EST 2012. Contains 205689 sequences.