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 A308007 #17 May 16 2019 18:39:39 %S A308007 1,2,3,4,5,6,9,7,8,14,10,11,18,12,13,24,15,16,30,17,19,34,20,21,39,22, %T A308007 23,43,25,26,50,27,28,54,29,31,57,33,32,35,36,70,37,38,73,40,41,78,42, %U A308007 44,85,45,46,90,47,48,94,49,51,97,52,53,104,55,56,109,58,59,116,61,60,62,63 %N A308007 Absolute values of first differences of A081145. %C A308007 The (signed) differences themselves are in A099004, but this sequence is important enough to have its own entry. %C A308007 Conjectured (see the Slater-Velez and Velez articles) to be a permutation of the positive integers. %C A308007 It appears that the terms line on two lines (this is true for the first million terms): see A308016-A308020. %H A308007 Chai Wah Wu, <a href="/A308007/b308007.txt">Table of n, a(n) for n = 1..5000</a> %H A308007 P. J. Slater and W. Y. Velez, <a href="http://projecteuclid.org/euclid.pjm/1102811644">Permutations of the Positive Integers with Restrictions on the Sequence of Differences</a>, Pacific Journal of Mathematics, Vol. 71, No. 1, 1977, 193-196. %H A308007 P. J. Slater and W. Y. Velez, <a href="https://projecteuclid.org/euclid.pjm/1102784895">Permutations of the Positive Integers with Restrictions on the Sequence of Differences, II</a>, Pacific Journal of Mathematics, Vol. 82, No. 2, 1979, 527-531. %H A308007 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 A308007 Cf. A081145, A081146, A099004, A308021. %Y A308007 See also A308016-A308020. %K A308007 nonn %O A308007 1,2 %A A308007 _N. J. A. Sloane_, May 13 2019