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A131881 Complement of A116700. Might be called "punctual birds". 9
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 25, 26, 27, 28, 29, 30, 33, 35, 36, 37, 38, 39, 40, 44, 46, 47, 48, 49, 50, 55, 57, 58, 59, 60, 66, 68, 69, 70, 77, 79, 80, 88, 90, 100, 102, 103, 104, 105, 106, 107, 108, 109, 113, 114 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Numbers n that do not occur in the concatenation of 1,2,3...,n-1.

Every power of 10 is a member, which proves that the sequence is infinite. - N. J. A. Sloane (njas(AT)research.att.com), Jul 23 2007

LINKS

M. F. Hasler, Table of n, a(n) for n = 1..2428

EXAMPLE

The first number not in this sequence is the early bird "12" which occurs as concatenation of 1 and 2.

PROG

(PHP) <?php $s="."; for(; ++$i < 2000; $s .= $i) if( !strpos($s, "$i")) echo $i, ", ";

CROSSREFS

Cf. A116700 (early birds).

Sequence in context: A023753 A035332 A048991 * A053460 A065200 A107909

Adjacent sequences:  A131878 A131879 A131880 * A131882 A131883 A131884

KEYWORD

nonn,base

AUTHOR

M. F. Hasler (maximilian.hasler(AT)gmail.com), Jul 23 2007

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Last modified February 14 06:53 EST 2012. Contains 205577 sequences.