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 A278860 #12 Aug 08 2025 05:00:06
%S A278860 1,1,92,7207016256,22448940392028699561050505216,
%T A278860 462177945344267713413229252637478222244311831261385379020800000
%N A278860 First series of Hankel determinants based on hyperfactorial.
%C A278860 It would be interesting to know the formula for this sequence.
%p A278860 a:= n-> LinearAlgebra[Determinant](Matrix(n, (i, j)->
%p A278860 (t-> mul(k^k, k=0..t))(i+j-1))):
%p A278860 seq(a(n), n=0..6); # _Alois P. Heinz_, Nov 29 2016
%t A278860 Table[Det[Table[Hyperfactorial[i + j - 1], {i, n}, {j, n}]], {n, 7}]
%Y A278860 Cf. A002109, A277829, A278770.
%K A278860 nonn
%O A278860 0,3
%A A278860 _Karol A. Penson_, Nov 29 2016