

A053169


A paradoxical sequence: a positive integer n is in this sequence if and only if n is not in sequence A_n in the database.


2



4, 7, 9, 11, 12, 13, 15, 17, 18, 20, 21, 22, 23, 24, 25, 28, 29, 30, 31, 32, 33, 34, 35, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 53, 54, 55, 56, 57, 58, 60, 61, 63, 64, 65, 66, 67, 68, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

"Not in sequence A_n" means not in the full list of terms, not simply in the list of terms visible in the entry.
The paradox is of course: is 53169 in this sequence?
Is 53873 in this sequence?  Tanya Khovanova, Aug 09 2007


REFERENCES

Smullyan, Raymond M, What is the name of this book? : The riddle of Dracula and other logical puzzles, Englewood Cliffs, NJ : PrenticeHall, c1978, see puzzle 163.


LINKS

Table of n, a(n) for n=1..81.


EXAMPLE

Sequence A000001 contains 1, so 1 is not in the sequence; A000002 contains 2, so 2 is not in the sequence; ...


CROSSREFS

Cf. A037181.
Complement of A053873.
Sequence in context: A234429 A153001 A010454 * A007656 A159619 A207017
Adjacent sequences: A053166 A053167 A053168 * A053170 A053171 A053172


KEYWORD

nonn,nice


AUTHOR

Miklos Szabo (mike(AT)ludens.elte.hu), N. J. A. Sloane, Tue Feb 29 2000


EXTENSIONS

Thanks to Alexander Hulpke (ahulpke(AT)math.ohiostate.edu) for the information that 19 is in A000019.
Extended to n=100 by N. J. A. Sloane, May 26 2007


STATUS

approved



