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A105314 Write the natural numbers as an infinite sequence of digits, starting at the left; a(n) is the subset (i.e., the position in this sequence of the "counting digits") of the first digit of the n-th square. 0
1, 4, 9, 22, 40, 62, 88, 118, 152, 190, 253, 322, 397, 478, 565, 658, 757, 862, 973, 1090, 1213, 1342, 1477, 1618, 1765, 1918, 2077, 2242, 2413, 2590, 2773, 2986, 3246, 3514, 3790, 4074, 4366, 4666, 4974, 5290, 5614, 5946, 6286, 6634, 6990, 7354, 7726, 8106 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..48.

EXAMPLE

integers  : 1234567891011121314151617...

1st digit : x  x    x            x

positions : 1  4    9           22

PROG

(PARI) a(n) = 1+ sum(k=1, n^2-1, #digits(k)); \\ Michel Marcus, Jul 27 2017

CROSSREFS

Cf. A103575.

Sequence in context: A041943 A158140 A290647 * A200155 A002835 A253289

Adjacent sequences:  A105311 A105312 A105313 * A105315 A105316 A105317

KEYWORD

base,easy,nonn

AUTHOR

Alexandre Wajnberg, Apr 25 2005

EXTENSIONS

More terms from Joshua Zucker, Jun 21 2006

STATUS

approved

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Last modified September 19 17:08 EDT 2020. Contains 337178 sequences. (Running on oeis4.)