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.

A253394 Number of (n+1) X (5+1) 0..1 arrays with every 2 X 2 subblock antidiagonal maximum minus diagonal minimum nondecreasing horizontally and diagonal maximum minus antidiagonal minimum nondecreasing vertically.

Original entry on oeis.org

304, 250, 316, 465, 666, 932, 1269, 1693, 2201, 2814, 3527, 4360, 5309, 6394, 7611, 8980, 10497, 12182, 14031, 16064, 18277, 20690, 23299, 26124, 29161, 32430, 35927, 39672, 43661, 47914, 52427, 57220, 62289, 67654, 73311, 79280, 85557, 92162, 99091
Offset: 1

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Author

R. H. Hardin, Dec 31 2014

Keywords

Examples

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

Crossrefs

Column 5 of A253397.

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) - 2*a(n-3) + 3*a(n-4) - a(n-5) for n>13.
Empirical for n mod 2 = 0: a(n) = (4/3)*n^3 + 13*n^2 + (5/3)*n + 164 for n>8.
Empirical for n mod 2 = 1: a(n) = (4/3)*n^3 + 13*n^2 + (5/3)*n + 161 for n>8.
Empirical g.f.: x*(304 - 662*x + 174*x^2 + 625*x^3 - 509*x^4 + 50*x^5 + 37*x^6 + 3*x^7 - 9*x^8 + 5*x^9 - 2*x^10 - x^11 + x^12) / ((1 - x)^4*(1 + x)). - Colin Barker, Dec 12 2018