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A211348 Number of ways to tile an n X n square with 1 X 1, 2 X 2 and 3 X 3 tiles. 2
1, 1, 2, 6, 39, 467, 10290, 431842, 33702357, 4933399675, 1353257600290, 694985665826606, 668743276018647665, 1205268925168096642391, 4069023157203412697840109, 25732126785058509461002703360, 304814553338563601845965453449729 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..16.

MAPLE

b:= proc(n, l) option remember; local i, k, s, t;

      if max(l[])>n then 0 elif n=0 then 1

    elif min(l[])>0 then t:=min(l[]); b(n-t, map(h->h-t, l))

    else for k do if l[k]=0 then break fi od; s:=0;

         for i from k to min(k+2, nops(l)) while l[i]=0 do s:=s+

           b(n, [l[j]$j=1..k-1, 1+i-k$j=k..i, l[j]$j=i+1..nops(l)])

         od; s

      fi

    end:

a:= n-> b(n, [0$n]):

seq(a(n), n=0..10);  # Alois P. Heinz, Feb 05 2013

CROSSREFS

Cf. A045846, A063443.

Sequence in context: A118324 A060421 A054970 * A295912 A120492 A028300

Adjacent sequences:  A211345 A211346 A211347 * A211349 A211350 A211351

KEYWORD

nonn

AUTHOR

Geoffrey H. Morley, Feb 05 2013

EXTENSIONS

a(7)-a(16) from Alois P. Heinz, Feb 05 2013

STATUS

approved

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Last modified July 16 04:26 EDT 2019. Contains 325064 sequences. (Running on oeis4.)