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A204237 Symmetric matrix given by f(i,j)=max(3i-j,3j-i). 4
2, 5, 5, 8, 4, 8, 11, 7, 7, 11, 14, 10, 6, 10, 14, 17, 13, 9, 9, 13, 17, 20, 16, 12, 8, 12, 16, 20, 23, 19, 15, 11, 11, 15, 19, 23, 26, 22, 18, 14, 10, 14, 18, 22, 26, 29, 25, 21, 17, 13, 13, 17, 21, 25, 29, 32, 28, 24, 20, 16, 12, 16, 20, 24, 28, 32, 35, 31, 27, 23 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..70.

EXAMPLE

Northwest corner:

2....5....8....11...14...17

5....4....7....10...13...16

8....7....6....9....12...15

11...10...9....8....11...14

14...13...12...11...10...13

MATHEMATICA

f[i_, j_] := Max[3 i - j, 3 j - i];

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}]]  (* A204237 *)

Table[Det[m[n]], {n, 1, 22}]  (* A204238 *)

Permanent[m_] :=

  With[{a = Array[x, Length[m]]},

   Coefficient[Times @@ (m.a), Times @@ a]];

Table[Permanent[m[n]], {n, 1, 14}] (* A204239 *)

CROSSREFS

Cf. A204238, A204239.

Sequence in context: A194531 A092394 A027438 * A153162 A168199 A251736

Adjacent sequences:  A204234 A204235 A204236 * A204238 A204239 A204240

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling, Jan 13 2012

STATUS

approved

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Last modified August 21 06:54 EDT 2019. Contains 326162 sequences. (Running on oeis4.)