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.

A207859 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 0 1 vertically.

Original entry on oeis.org

10, 100, 370, 1369, 7289, 38809, 178088, 817216, 3976696, 19351201, 91961095, 437019025, 2096687880, 10059287616, 48075784344, 229765876921, 1099823682601, 5264542102681, 25183871849968, 120471522306304, 576445792593008
Offset: 1

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Author

R. H. Hardin Feb 21 2012

Keywords

Comments

Row 4 of A207858

Examples

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

Formula

Empirical: a(n) = 2*a(n-1) +30*a(n-3) +161*a(n-4) +45*a(n-5) +166*a(n-6) -749*a(n-7) -4860*a(n-8) -1352*a(n-9) +3048*a(n-10) +4635*a(n-11) +28540*a(n-12) +11318*a(n-13) -11422*a(n-14) -4202*a(n-15) -69991*a(n-16) -28677*a(n-17) +609*a(n-18) -20891*a(n-19) +65400*a(n-20) +5094*a(n-21) +7969*a(n-22) +10090*a(n-23) -24802*a(n-24) +1479*a(n-25) -2070*a(n-26) -1380*a(n-27) +3917*a(n-28) -350*a(n-29) -75*a(n-30) +41*a(n-31) -140*a(n-32) +16*a(n-33) +a(n-35) +a(n-36)