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 A098926 Permanent of the (0,1)-matrix with ij-th entry equal to zero iff (i=1,j=1),(i=1,j=2),(i=1,j=3),(i=2,j=3),(i=3,j=3),... In other words, the ij-th entry of the matrix is zero iff it is on the path which start from the entry (i=1,j=1) and moves in the matrix alternating 3 steps to the right to 3 steps down. 0
 0, 2, 12, 90, 556, 5242, 42380, 479306, 4817484, 63779034, 767504524, 11661506218, 163541678156, 2806878055610, 44960579074956, 860568917787402, 15502269624912460, 327460573946510746, 6552868832109180044, 151436547414562736234, 3332986639447590230604, 83655126041771262574458 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,2 LINKS EXAMPLE a(3) = 12 because 12 is the permanent of the following 5 X 5 matrix:     [0 0 0 1 1]     [1 1 0 1 1]     [1 1 0 0 0]     [1 1 1 1 0]     [1 1 1 1 0] PROG (PARI) a(n)={my(M=matrix(n, n, i, j, j-i<>1 && (i%2==0 || abs(j-i-1)<>1))); matpermanent(M)} \\ Andrew Howroyd, Nov 05 2019 CROSSREFS Sequence in context: A224152 A174356 A121357 * A074610 A250130 A225573 Adjacent sequences:  A098923 A098924 A098925 * A098927 A098928 A098929 KEYWORD nonn AUTHOR Simone Severini, Oct 19 2004 EXTENSIONS Terms a(11) and beyond from Andrew Howroyd, Nov 05 2019 STATUS approved

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Last modified January 19 03:54 EST 2020. Contains 331031 sequences. (Running on oeis4.)