cp's OEIS Frontend

A201700 T(n,k)=Number of nXk 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.

%I A201700 #7 Jul 22 2025 16:19:25
%S A201700 3,3,3,3,10,3,3,18,18,3,3,27,116,27,3,3,37,395,395,37,3,3,48,989,4998,
%T A201700 989,48,3,3,60,2068,35390,35390,2068,60,3,3,73,3838,167625,930564,
%U A201700 167625,3838,73,3,3,87,6541,607919,14268351,14268351,607919,6541,87,3,3,102
%N A201700 T(n,k)=Number of nXk 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.
%C A201700 Table starts
%C A201700 .3...3.....3........3...........3..............3...............3
%C A201700 .3..10....18.......27..........37.............48..............60
%C A201700 .3..18...116......395.........989...........2068............3838
%C A201700 .3..27...395.....4998.......35390.........167625..........607919
%C A201700 .3..37...989....35390......930564.......14268351.......142436489
%C A201700 .3..48..2068...167625....14268351......795339012.....27102769900
%C A201700 .3..60..3838...607919...142436489....27102769900...3262897246338
%C A201700 .3..73..6541..1826778..1034563890...615440785548.253484699853930
%C A201700 .3..87.10455..4775228..5898023820.10106227864338
%C A201700 .3.102.15894.11211034.27803725006
%H A201700 R. H. Hardin, <a href="/A201700/b201700.txt">Table of n, a(n) for n = 1..112</a>
%e A201700 Some solutions for n=5 k=3
%e A201700 ..0..0..2....0..0..2....0..2..2....0..1..2....0..1..2....0..2..2....0..1..2
%e A201700 ..0..2..1....0..0..2....0..2..2....1..0..2....1..0..1....0..2..2....0..2..0
%e A201700 ..2..0..1....0..1..0....2..1..2....1..0..2....1..0..1....1..0..2....0..2..0
%e A201700 ..2..0..1....1..0..0....2..1..2....1..0..2....1..0..1....1..1..0....1..1..0
%e A201700 ..2..2..0....1..0..0....2..2..1....2..2..1....1..1..0....2..0..0....2..0..0
%Y A201700 Column 2 is A051938(n+5)
%K A201700 nonn,tabl
%O A201700 1,1
%A A201700 _R. H. Hardin_ Dec 03 2011