A252827 Number of n X 7 nonnegative integer arrays with upper left 0 and every value within 3 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

42, 729, 10761, 125892, 1165921, 8807722, 55960651, 306796310, 1481748658, 6411737114, 25203579317, 91037124979, 305083525901, 956286103952, 2823092600299, 7895877354183, 21029532417878, 53571661955209

Offset

1,1

Comments

Column 7 of A252828.

Links

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

Formula

Empirical: a(n) = (491/510909421717094400)*n^21 + (491/4054836680294400)*n^20 + (31237/4561691265331200)*n^19 + (16931/72754246656000)*n^18 + (6860417/1280474741145600)*n^17 + (5620079/62768369664000)*n^16 + (28238557/24715045555200)*n^15 + (460207/39626496000)*n^14 + (1996189759/20542375526400)*n^13 + (9849852413/14485008384000)*n^12 + (262128023/65840947200)*n^11 + (23507656471/1207084032000)*n^10 + (126607207245823/1581762915532800)*n^9 + (1573022155907/5706215424000)*n^8 + (887749472755/1129830653952)*n^7 + (43972723546711/23538138624000)*n^6 + (101853364790929/26676557107200)*n^5 + (13152985155929/2020951296000)*n^4 + (11601438763393/1119943843200)*n^3 + (5765297083043/586637251200)*n^2 + (131188073/15519504)*n.

Example

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

Crossrefs

Cf. A252828.

Sequence in context: A159947 A330845 A333113 * A231158 A030197 A225980

Adjacent sequences: A252824 A252825 A252826 * A252828 A252829 A252830

Keyword

nonn

Author

R. H. Hardin, Dec 22 2014

Status

approved