A183646 Number of (n+1) X 4 0..4 arrays with every 2 X 2 subblock summing to 8.

1333, 3445, 10213, 33325, 116653, 431125, 1664533, 6663805, 27510973, 116631205, 506044453, 2240844685, 10102562893, 46271013685, 214876977973, 1009929047965, 4796169800413, 22979947770565, 110935048993093, 538933057705645

Offset

1,1

Comments

Column 3 of A183652.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 15*a(n-1) - 85*a(n-2) + 225*a(n-3) - 274*a(n-4) + 120*a(n-5).

Empirical g.f.: x*(1333 - 16550*x + 71843*x^2 - 126970*x^3 + 75000*x^4) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)). - Colin Barker, Apr 01 2018

Example

Some solutions for 3 X 4:
  0 2 0 4     1 3 2 1     1 3 1 4     2 2 4 1     3 3 3 2
  2 4 2 2     2 2 1 4     0 4 0 3     3 1 1 2     2 0 2 1
  2 0 2 2     2 2 3 0     1 3 1 4     1 3 3 2     3 3 3 2

Crossrefs

Cf. A183652.

Sequence in context: A003907 A043613 A028501 * A250902 A250946 A145494

Adjacent sequences: A183643 A183644 A183645 * A183647 A183648 A183649

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved