A087931 Number of ways of arranging the numbers 1 ... 10n into a 10 X n array so there is exactly one local maximum.
512, 3020819005440, 2980039854936078219167744
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.