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 A276688 #7 Feb 16 2025 08:33:36
%S A276688 0,0,1,8,5,-220,1895,-9140,-302175,-2778300,-95631825,-10071428100,
%T A276688 -236788407375,57706241794500,-7412904844112625,525300693117661500,
%U A276688 348922898045520800625,55166584329677385922500,28368558145043150339199375,46873210124734003815040957500
%N A276688 a(n) = Im([n]_{1+i}!), where [n]_q! is the q-factorial, i = sqrt(-1).
%H A276688 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/q-Factorial.html">q-Factorial</a>.
%p A276688 a:= n-> Im(mul(((1+I)^j-1)/((1+I)-1), j=1..n)):
%p A276688 seq(a(n), n=0..20); # _Alois P. Heinz_, Sep 14 2016
%t A276688 Im@Table[QFactorial[n, 1 + I], {n, 0, 20}]
%Y A276688 Cf. A275706 (real part), A005329.
%K A276688 sign
%O A276688 0,4
%A A276688 _Vladimir Reshetnikov_, Sep 13 2016