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.

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

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?

References

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

Links

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

Index entries for sequences whose definition involves A_n (or An).

Example

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

Crossrefs

Cf. A107357.

Complement of A053873.

Sequence in context: A310941 A310942 A273916 * A007656 A159619 A272454

Adjacent sequences: A053166 A053167 A053168 * A053170 A053171 A053172

Keyword

nonn,nice

Author

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

Extensions

Thanks to Alexander Hulpke for the information that 19 is in A000019.

Extended to n=100 by N. J. A. Sloane, May 26 2007

Status

approved