This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A097481 #19 Nov 26 2015 23:55:17 %S A097481 24,6,8,10,12,14,16,18,20,2,224,26,28,30,32,34,36,38,40,4,244,46,48, %T A097481 50,52,54,56,58,60,62,64,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94, %U A097481 96,98,100,102,104,106,108,110,112,114,116,118,120,122,124,126,128,130,132 %N A097481 Write the positive even integers on labels in numerical order, forming an infinite sequence L. Consider the succession of digits of L: 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 4 2 6 2 8 3 0 ... (A036211). This sequence gives a derangement of L that produces the same succession of digits, subject to the constraint that the smallest unused label must be used that does not lead to a contradiction. %C A097481 Derangement here means the n-th element of L is not the n-th element of this sequence, so a(n) != 2n. %e A097481 We must begin with 2,4,6,8,... and we cannot have a(1) = 2, so the first possibility is the label "24". The next term must be the smallest available label not leading to a contradiction, thus "6". The next one will be "8", etc. After the label "20" the smallest available label is "2". After this "2" we cannot have a(11) = 22 -- we thus take the smallest available label which is "224". No label is allowed to start with a leading zero. %Y A097481 Cf. A005843, A097484. %K A097481 base,easy,nonn %O A097481 1,1 %A A097481 _Eric Angelini_, Sep 19 2004 %E A097481 Corrected and extended by _Jacques ALARDET_ and _Eric Angelini_, Aug 12 2008 %E A097481 Derangement wording introduced by _Danny Rorabaugh_, Nov 26 2015