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 A060963 #33 Feb 19 2020 01:15:18
%S A060963 1,1,1,5,29,145,957,8397,85169,944221,11639417,160699437,2430145085,
%T A060963 39776366397,703161838717,13369111112753,271734091323897
%N A060963 Number of pairings of the first 2n positive integers so that the absolute differences of each pair are different.
%C A060963 Number of perfect Skolem-type sequences.
%H A060963 Edward Moody, <a href="https://github.com/EdwardMGraphite/generalised-langford">Java program for calculating entries in this sequence and A322178</a>
%H A060963 G. Nordh, <a href="https://arxiv.org/abs/math/0506155">Perfect Skolem sequences</a>, arXiv:math/0506155 [math.CO], 2005.
%e A060963 a(3)=5 since the 5 pairings of {1, 2, 3, 4, 5, 6} are {1, 3} {2, 6} {4, 5}, {1, 5} {2, 3} {4, 6}, {1, 5} {2, 4} {3, 6}, {1, 4} {2, 6} {3, 5}, {1, 6} {2, 5} {3, 4}.
%Y A060963 Cf. A261516, A261517, A322178.
%K A060963 nonn,more
%O A060963 0,4
%A A060963 _Erich Friedman_, May 08 2001
%E A060963 Offset corrected by _Alois P. Heinz_, Sep 14 2015
%E A060963 a(14) from _Fausto A. C. Cariboni_, Mar 03 2017
%E A060963 a(15) from _Fausto A. C. Cariboni_, Apr 10 2017
%E A060963 a(16) from _Edward Moody_, Feb 17 2020