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 A102046 #16 Feb 21 2021 13:40:34 %S A102046 1,1,2,6,7,8,720,721,722,723,724,726,727,728,729,780,781,782,783,784, %T A102046 785,786,787,789,790,791,792,793,794,795,796,797,798,799,780,781,782, %U A102046 783,784,785,786,787,788,789,790,791,792,793,794,795,796,797,798,799 %N A102046 Smallest positive integer greater than a(n - 1) consistent with the condition that n is a member of the sequence if and only if a(n) is congruent to (n!)!. %C A102046 The sequence is related to the fake even and fake odd sequences and also the factorial and double factorial sequences, so seems in the short run linear but in the long run exponential. %F A102046 a(a(n)) = (n!)! %e A102046 a(6) = 720 because (3!)! = 6! = 720 %Y A102046 Cf. A080591, A080588, A000197, A000142. %K A102046 easy,nonn,obsc %O A102046 0,3 %A A102046 _Michael Joseph Halm_, Feb 12 2005 %E A102046 The definition does not match the data. How was this sequence generated? - _N. J. A. Sloane_, Feb 21 2021