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 A101886 #5 Jan 21 2014 12:17:58 %S A101886 1,2,3,5,6,7,9,10,11,14,15,16,18,19,20,22,24,27,28,29,31,32,35,36,37, %T A101886 39,41,42,43,47,48,50,51,53,55,58,60,61,63,65,66,68,70,71,72,77,78,80, %U A101886 82,85,86,87,89,90,91,94,95,96,98,99,100,102,103,104,107,109,110,111,114 %N A101886 Smallest natural number sequence without any length 4 equidistant arithmetic subsequences. %e A101886 4 is out because of 1,2,3,4. 13 is out because of 1,5,9,13. %Y A101886 Cf. A101887, A101884, A101888. %Y A101886 A selection of sequences related to "no three-term arithmetic progression": A003002, A003003, A003278, A004793, A005047, A005487, A033157, A065825, A092482, A093678, A093679, A093680, A093681, A093682, A094870, A101884, A101886, A101888, A140577, A185256, A208746, A229037. %K A101886 nonn %O A101886 1,2 %A A101886 Douglas Stones (dssto1(AT)student.monash.edu.au), Dec 20 2004