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A125120 Sum of values of repunits of length n in base b representation with 1<b<=n+1. 1
1, 7, 41, 296, 2829, 34637, 519049, 9197344, 188039787, 4356087231, 112754069273, 3224945523736, 100999970565337, 3437517630509497, 126332966608699441, 4986057436997869696, 210331809309776028055, 9443995455881145458715 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Sums of rows of the triangle in A125118: a(n)=Sum(A125118(n,k):1<=k<=n).

LINKS

Table of n, a(n) for n=1..18.

Eric Weisstein's World of Mathematics, Repunit

FORMULA

a(n) = Sum(Sum((k+1)^i: 0<=i<k): 1<=k<=n).

EXAMPLE

a(4) = [1111]_2 + [1111]_3 + [1111]_4 + [1111]_5 =

((2+1)*2+1)*2+1 + ((3+1)*3+1)*3+1 + ((4+1)*4+1)*4+1 +

((5+1)*5+1)*5+1 = 296.

CROSSREFS

Sequence in context: A258941 A080047 A297671 * A181441 A290044 A209113

Adjacent sequences:  A125117 A125118 A125119 * A125121 A125122 A125123

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkellerlhsystems.com), Nov 21 2006

STATUS

approved

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Last modified July 15 04:34 EDT 2020. Contains 335763 sequences. (Running on oeis4.)