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A125119 Values of repunits with odd length L in base (L+3)/2 representation. 1
1, 13, 341, 19531, 2015539, 329554457, 78536544841, 25736391511831, 11111111111111111, 6115909044841454629, 4182283628124518315101, 3479492117784426363920483, 3461445831219105624193478971 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Central terms of the triangle in A125118: a(n)=A125118(2*n-1,n).

LINKS

Table of n, a(n) for n=1..13.

Eric Weisstein's World of Mathematics, Repunit

FORMULA

a(n) = Sum((n+1)^k: 0<=k<=2*(n-1)).

EXAMPLE

a(4) = [1111111]_5 = (((((5+1)*5+1)*5+1)*5+1)*5+1)*5+1 = 19531.

CROSSREFS

Sequence in context: A041312 A096717 A296679 * A160396 A253125 A297070

Adjacent sequences:  A125116 A125117 A125118 * A125120 A125121 A125122

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Nov 21 2006

STATUS

approved

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Last modified July 9 18:08 EDT 2020. Contains 335545 sequences. (Running on oeis4.)