A280899 Number of nX5 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

2, 2292, 492490, 65348136, 7083739466, 684011230518, 61277484218852, 5208435552362140, 425813044528570428, 33785008405748220928, 2617623231970413715570, 198929682493832699515942

Offset

1,1

Comments

Column 5 of A280902.

Links

R. H. Hardin, Table of n, a(n) for n = 1..109

Formula

Empirical: a(n) = 177*a(n-1) -9639*a(n-2) +107900*a(n-3) +2883885*a(n-4) +5871669*a(n-5) -87408440*a(n-6) -250798851*a(n-7) +1108602915*a(n-8) +2445033196*a(n-9) -8693276349*a(n-10) +921374187*a(n-11) +45823231665*a(n-12) -105612340278*a(n-13) -17974034580*a(n-14) +256947247648*a(n-15) -764890720464*a(n-16) +786528800352*a(n-17) -1082015830016*a(n-18) +590857620864*a(n-19) -784830044928*a(n-20) +120654596096*a(n-21) -298074921984*a(n-22) -3182462976*a(n-23) -41854210048*a(n-24) for n>27

Example

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

Crossrefs

Cf. A280902.

Sequence in context: A051103 A005800 A200170 * A288164 A133074 A280312

Adjacent sequences: A280896 A280897 A280898 * A280900 A280901 A280902

Keyword

nonn

Author

R. H. Hardin, Jan 10 2017

Status

approved