A108968 Self-ranked numbers.

1, 2, 5, 8, 9, 12, 14, 20, 23, 25, 49, 51, 52, 78, 82, 91, 114, 144, 145, 149, 151, 185, 202, 211, 225, 231, 251, 252, 411, 418, 420, 441, 446, 491, 512, 514, 541, 582, 782, 820, 821, 854, 914, 978, 1144, 1191, 1420, 1441, 1446, 1452, 1491, 1514, 1521, 1854, 1911

Offset

0,2

References

GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See page 41, Problem 67 (a subsequence).

Links

Table of n, a(n) for n=0..54.

Example

"1" is in the sequence because if you replace each letter of "one" by its rank in the alphabet you get the string 15145 which contains at least a "1".
["3" produces the string 2081855 which contains no "3" -- thus "3" is not a "self-ranked number".]

Crossrefs

Sequence in context: A174438 A176061 A183234 * A289628 A047387 A063282

Adjacent sequences: A108965 A108966 A108967 * A108969 A108970 A108971

Keyword

base,easy,nonn,word

Author

Eric Angelini, Jul 26 2005

Extensions

More terms from Sean A. Irvine, Mar 04 2010

Status

approved