A187612 Number of 8-step one space for components leftwards or up, two space for components rightwards or down asymmetric quasi-bishop's tours (antidiagonal moves become knight moves) on an n X n board summed over all starting positions.

0, 0, 0, 0, 0, 474, 3780, 12946, 32869, 68308, 117760, 187311, 275272, 379035, 500919, 639115, 793623, 964443, 1151575, 1355019, 1574775, 1810843, 2063223, 2331915, 2616919, 2918235, 3235863, 3569803, 3920055, 4286619, 4669495, 5068683, 5484183

Offset

1,6

Comments

Row 8 of A187606.

Links

R. H. Hardin, Table of n, a(n) for n = 1..50

Formula

Empirical: a(n) = 8156*n^2 - 114640*n + 385419 for n>13.

Conjectures from Colin Barker, Apr 25 2018: (Start)

G.f.: x^6*(474 + 2358*x + 3028*x^2 + 4897*x^3 + 4759*x^4 - 1503*x^5 + 6086*x^6 - 1689*x^7 - 2608*x^8 + 2319*x^9 - 1809*x^10) / (1 - x)^3.

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>16.

(End)

Crossrefs

Cf. A187606.

Sequence in context: A348806 A370295 A045302 * A237679 A236776 A236636

Adjacent sequences: A187609 A187610 A187611 * A187613 A187614 A187615

Keyword

nonn

Author

R. H. Hardin, Mar 11 2011

Status

approved