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 A129199 #10 Feb 24 2019 11:32:34 %S A129199 1,3,2,8,4,16,19,43,5,53,6,102,185,377,7,391,759,1527,9,1545,3062, %T A129199 6134,10,6154,12277,24565,11,24587,12,49164,98291,196595,13,196621, %U A129199 393202,786418,14,786446,1572849,3145713,15,3145743,6291440,12582896,12582895 %N A129199 Absolute differences of A129198. %C A129199 This sequence is known to be a permutation of positive integers, along with its parent sequence (A129198). %C A129199 In the paper of Slater and Velez it is shown that both this sequence and its parent are permutations of positive integers. %H A129199 P. J. Slater and W. Y. Velez, <a href="https://projecteuclid.org/euclid.pjm/1102811644">Permutations of the Positive Integers with Restrictions on the Sequence of Differences</a>, Pacific J. Math., 71, 1977. %H A129199 William Y. Velez, <a href="https://doi.org/10.1016/0012-365X(92)90724-T">Research problems 159-160</a>, Discrete Math 110 (1992), pp. 301-302. %Y A129199 This is the absolute difference of A129198, cf. A081145. %K A129199 nonn %O A129199 1,2 %A A129199 Ferenc Adorjan (fadorjan(AT)freemail.hu or ferencadorjan(AT)gmail.com), Apr 04 2007