A123794 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 6.
1, 24, 1861, 168661, 16902651, 1797062518, 199090941069
Offset: 1
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.