OFFSET
1,1
COMMENTS
This could be roughly rephrased like this: Rewrite in the most economical way the "multiples-of-3 pattern" using only multiples of 3, but rearranged. No term in the sequence can appear more than once.
Derangement here means the n-th element of L is not the n-th element of this sequence, so a(n) != 3n.
EXAMPLE
We must begin with 3,6,9,12,... and we cannot have a(1) = 3, so the first possibility is the label "36". The next term must be the smallest available label not leading to a contradiction, thus "9". The next one will be "12", etc. After the label "30" the smallest available label is "3". After this "3" we cannot have a(11) = 33 -- we thus take the smallest available label which is "336". No label is allowed to start with a leading zero. - Eric Angelini, Aug 12 2008
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Eric Angelini, Sep 19 2004
EXTENSIONS
Corrected and extended by Jacques ALARDET and Eric Angelini, Aug 12 2008
Derangement wording introduced by Danny Rorabaugh, Nov 26 2015
STATUS
approved