cp's OEIS Frontend

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.

A239601 Number of 3Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.

Original entry on oeis.org

4, 4, 31, 187, 1310, 9806, 76769, 611126, 4929897, 39990616, 325367130, 2651480323, 21625911002, 176464323565, 1440276473432, 11756877845964, 95977420564389, 783542978550992, 6396841387070227, 52224370266137630, 426366892135459667
Offset: 1

Views

Author

R. H. Hardin, Mar 22 2014

Keywords

Comments

Row 3 of A239599

Examples

			Some solutions for n=4
..3..2..2..0....3..2..2..0....3..0..0..2....3..0..0..2....3..2..2..2
..2..1..0..2....2..1..2..2....2..3..0..0....2..3..0..0....2..1..0..2
..3..2..0..0....3..2..0..0....3..1..2..0....3..2..2..0....3..2..0..2