A165145 - OEIS

A165145

Partial sums of A058183.

1, 3, 6, 10, 15, 21, 28, 36, 45, 56, 69, 84, 101, 120, 141, 164, 189, 216, 245, 276, 309, 344, 381, 420, 461, 504, 549, 596, 645, 696, 749, 804, 861, 920, 981, 1044, 1109, 1176, 1245, 1316, 1389, 1464, 1541, 1620, 1701, 1784, 1869, 1956, 2045, 2136, 2229, 2324, 2421

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OFFSET

1,2

COMMENTS

Number of digits of the concatenated first n entries of A007908.

LINKS

Table of n, a(n) for n=1..53.

EXAMPLE

Example: The 4th number is 10, because the number of digits in the concatenation 1121231234 is 10.

MATHEMATICA

t=Table[n*(n+1)/2, {n, 53}]; q=9; Add12[l_]:=Table[l[[n+q]]+l[[n]], {n, Length[l]-q}]; Join[Take[t, 9], Add12[t]] (* Vladimir Joseph Stephan Orlovsky, Feb 01 2012 *)

PROG

(Other) Visual Basic: Function Number(ByVal n As Long) Dim i As Long, b() ReDim b(n) For i = 1 To n b(i) = b(i - 1) + Len(CStr(i)) Number = Number + b(i) Next End Function

CROSSREFS

Sequence in context: A025746 A119663 A025715 * A046489 A277209 A361751

Adjacent sequences: A165142 A165143 A165144 * A165146 A165147 A165148

KEYWORD

easy,base,nonn

AUTHOR

Zhining Yang, Sep 05 2009

EXTENSIONS

Edited and extended by R. J. Mathar, Sep 06 2009

STATUS

approved