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A099102 Natural numbers n with fewer digits than sigma(n). 1
6, 8, 9, 48, 54, 56, 60, 63, 64, 66, 68, 70, 72, 74, 75, 76, 78, 80, 81, 82, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 360, 384, 390, 396, 408, 420, 432, 440, 444, 448, 450, 456, 460, 462, 468, 476, 480, 486, 490, 492, 498, 500, 504, 510, 512, 516, 520 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence is a comment on the referenced comment of R. K. Guy concerning the occurrence of 301-digit numbers.

LINKS

Table of n, a(n) for n=1..61.

R. K. Guy, Re: Odd Perfect Numbers, Sep 23 2004 post to NMBRTHRY mailing list.

EXAMPLE

6 is in the sequence because 1, the number of digits in 6, is less than 2, the number of digits in 12 = sigma(6).

PROG

(PARI) isok(n) = length(digits(n, 10)) < length(digits(sigma(n), 10)) \\ Michel Marcus, Jul 23 2013

CROSSREFS

Cf. A000203, A099103.

Sequence in context: A174213 A284990 A238621 * A001743 A256964 A046344

Adjacent sequences:  A099099 A099100 A099101 * A099103 A099104 A099105

KEYWORD

base,easy,nonn

AUTHOR

Walter Nissen, Sep 25 2004

STATUS

approved

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Last modified March 23 04:46 EDT 2019. Contains 321422 sequences. (Running on oeis4.)