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 A204252 Permanent of the n-th principal submatrix of A201208 (in square format). 1
 1, 5, 18, 132, 876, 8820, 85392, 1106496, 14057280, 223560000, 3513456000, 66305952000, 1241430624000, 27127003680000, 589395356928000, 14638710417408000, 362021985626112000, 10073602372700160000, 279369787588448256000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..19. MATHEMATICA f[i_, j_] := 1 + Mod[i + j, 2]; m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}] TableForm[m[8]] (* 8x8 principal submatrix *) Flatten[Table[f[i, n + 1 - i], {n, 1, 12}, {i, 1, n}]] (* A201208 in square format *) Permanent[m_] := With[{a = Array[x, Length[m]]}, Coefficient[Times @@ (m.a), Times @@ a]]; Table[Permanent[m[n]], {n, 1, 20}] (* A204252 *) CROSSREFS Cf. A201208. Sequence in context: A009365 A140296 A278172 * A281564 A291356 A091059 Adjacent sequences: A204249 A204250 A204251 * A204253 A204254 A204255 KEYWORD nonn AUTHOR Clark Kimberling, Jan 14 2012 STATUS approved

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Last modified November 29 00:31 EST 2023. Contains 367422 sequences. (Running on oeis4.)