A273961 Number of nX2 0..3 arrays with no three equal values forming an isosceles right triangle, and new values introduced in 0..3 order.

2, 10, 105, 1264, 15418, 188465, 2304141, 28171070, 344428103, 4211086174, 51486063258, 629484802987, 7696279187803, 94097130028610, 1150461107685501, 14065899352150196, 171974109566120666, 2102609553831755149

Offset

1,1

Comments

Column 2 of A273964.

Links

R. H. Hardin, Table of n, a(n) for n = 1..46

Formula

Empirical: a(n) = 14*a(n-1) -18*a(n-2) -54*a(n-3) +112*a(n-4) -30*a(n-5) -41*a(n-6) +18*a(n-7) for n>8

Empirical g.f.: 2*x -x^2*(10-35*x-26*x^2+152*x^3-85*x^4-49*x^5+30*x^6) / ( (x-1) *(x^2+x-1) *(18*x^4-41*x^3+6*x^2+12*x-1) ). - R. J. Mathar, Jun 06 2016

Example

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

Crossrefs

Cf. A273964.

Sequence in context: A000595 A087234 A273965 * A365507 A049538 A217901

Adjacent sequences: A273958 A273959 A273960 * A273962 A273963 A273964

Keyword

nonn

Author

R. H. Hardin, Jun 05 2016

Status

approved