A233911 Number of (n+1)X(2+1) 0..7 arrays with every 2X2 subblock having the sum of the squares of the edge differences equal to 30, and no two adjacent values equal

640, 3944, 22632, 138132, 807964, 4908404, 28936484, 175407492, 1039210048, 6291984872, 37411050288, 226333090864, 1349436837188, 8159273967724, 48752105141528, 294639966341512, 1763518515517052, 10653925639599432

Offset

1,1

Comments

Column 2 of A233917

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 4*a(n-1) +122*a(n-2) -461*a(n-3) -6376*a(n-4) +22883*a(n-5) +188152*a(n-6) -648596*a(n-7) -3478827*a(n-8) +11715412*a(n-9) +42308852*a(n-10) -142371381*a(n-11) -345931578*a(n-12) +1197824103*a(n-13) +1908669954*a(n-14) -7078856586*a(n-15) -6995027392*a(n-16) +29551303874*a(n-17) +16143386244*a(n-18) -87052258170*a(n-19) -19433628990*a(n-20) +179619345422*a(n-21) -2128109482*a(n-22) -255775086626*a(n-23) +46189589396*a(n-24) +245226941694*a(n-25) -73044737386*a(n-26) -152167442028*a(n-27) +56827325500*a(n-28) +57294922304*a(n-29) -23672423108*a(n-30) -11706249412*a(n-31) +4940867468*a(n-32) +1040756704*a(n-33) -439680112*a(n-34) -20118176*a(n-35) +11155520*a(n-36) -250624*a(n-37) -14592*a(n-38)

Example

Some solutions for n=4
..2..0..2....2..6..2....0..4..3....1..4..1....6..5..6....0..1..0....0..3..7
..5..4..1....4..7..5....2..1..5....5..6..2....4..1..4....3..5..3....4..5..4
..2..0..2....2..6..2....6..3..2....1..3..1....3..5..3....0..1..0....6..2..6
..1..4..1....5..7..4....5..1..5....5..6..5....4..1..4....3..5..2....7..5..7
..5..3..5....6..3..2....3..4..6....7..3..7....3..5..3....7..4..6....3..6..3

Crossrefs

Sequence in context: A293922 A027885 A097105 * A178975 A170774 A290029

Adjacent sequences: A233908 A233909 A233910 * A233912 A233913 A233914

Keyword

nonn

Author

R. H. Hardin, Dec 17 2013

Status

approved