A220567 Number of ways to reciprocally link elements of an 6Xn array either to themselves or to exactly one horizontal or antidiagonal neighbor.

1, 233, 6076, 338581, 14298089, 665748170, 29955561052, 1363847439227, 61845935792336, 2808292682072854, 127461441592952329, 5786012622635830257, 262638882187378528534, 11921898805633926722093, 541164958214032363841199

Offset: 1

Author

R. H. Hardin Dec 16 2012

Keywords

• nonn

Comments

Row 6 of A220562

Examples

			Some solutions for n=3 0=self 3=ne 4=w 6=e 7=sw (reciprocal directions total 10)
..0..7..7....0..0..0....6..4..7....0..7..0....0..7..0....0..0..0....0..6..4
..3..3..0....6..4..0....0..3..0....3..6..4....3..7..0....6..4..0....6..4..7
..6..4..0....0..6..4....0..6..4....6..4..0....3..0..0....0..0..0....0..3..0
..0..0..0....6..4..7....6..4..0....0..7..0....0..7..0....0..0..0....0..0..7
..0..7..0....0..3..0....0..6..4....3..7..0....3..7..7....0..0..7....0..3..0
..3..0..0....0..6..4....0..6..4....3..6..4....3..3..0....0..3..0....6..4..0
		

Links

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

Formula

Empirical: a(n) = 13*a(n-1) +1348*a(n-2) +10654*a(n-3) -198504*a(n-4) -1906076*a(n-5) [phone]*a(n-6) [phone]*a(n-7) -925177576*a(n-8) -4891188529*a(n-9) [phone]*a(n-10) [phone]*a(n-11) -848296316904*a(n-12) -276758340388*a(n-13) [phone]*a(n-14) -7107958733596*a(n-15) -92787258095632*a(n-16) [phone]*a(n-17) [phone]*a(n-18) -774675289613655*a(n-19) -2182902615756840*a(n-20) +3555500220788694*a(n-21) +6973910104740084*a(n-22) -11426713159097796*a(n-23) -17667940720548336*a(n-24) +26747813225197794*a(n-25) +35945989169311476*a(n-26) -46394604844529149*a(n-27) -58560503957694547*a(n-28) +59946651607436776*a(n-29) +75473026016657552*a(n-30) -57619701988418728*a(n-31) -75893814357642448*a(n-32) +40983675195728936*a(n-33) +58931290214948032*a(n-34) -21385512054198856*a(n-35) -35152757210761395*a(n-36) +8057875480743783*a(n-37) +16091164614749124*a(n-38) -2117225467318182*a(n-39) -5658108579422624*a(n-40) [phone]*a(n-41) +1530178310024236*a(n-42) -22441127837162*a(n-43) -318296736753680*a(n-44) -5136539584403*a(n-45) [phone]*a(n-46) [phone]*a(n-47) -6199297816488*a(n-48) -263242733620*a(n-49) [phone]*a(n-50) [phone]*a(n-51) -39590221744*a(n-52) -1591760572*a(n-53) [phone]*a(n-54) [phone]*a(n-55) -72760800*a(n-56) -1863630*a(n-57) +1806100*a(n-58) +31300*a(n-59) -28744*a(n-60) -282*a(n-61) +260*a(n-62) +a(n-63) -a(n-64)