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A122365 The (1,6)-entry of the matrix M^n, where M is the 6 X 6 matrix {{1, 1, 1, 1, 1, 1},{1, 0, 0, 0, 1, 0},{1, 0, 0, 1, 0, 0},{1, 0, 1, 0, 0, 0},{1, 1, 0, 0, 0, 0}, {1, 0, 0, 0, 0, 0}}. 0
0, 1, 1, 6, 15, 53, 160, 517, 1621, 5150, 16267, 51513, 162944, 515673, 1631609, 5162966, 16336695, 51693645, 163571104, 517580093, 1637750957, 5182251182, 16397926099, 51887105969, 164183665152, 519517828081, 1643883210801 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

FORMULA

a(n)=2a(n-1)+5a(n-2)-3a(n-3)-4a(n-4)+a(n-5); a(0)=0, a(1)=1, a(2)=1,a(3)=6,a(4)=15 (follows from the minimal polynomial of M).

MAPLE

a[0]:=0: a[1]:=1: a[2]:=1: a[3]:=6: a[4]:=15: for n from 5 to 26 do a[n]:=2*a[n-1]+5*a[n-2]-3*a[n-3]-4*a[n-4]+a[n-5] od: seq(a[n], n=0..26);

MATHEMATICA

M = {{1, 1, 1, 1, 1, 1}, {1, 0, 0, 0, 1, 0}, {1, 0, 0, 1, 0, 0}, {1, 0, 1, 0, 0, 0}, {1, 1, 0, 0, 0, 0}, {1, 0, 0, 0, 0, 0}}; v[1] = {0, 0, 0, 0, 0, 1}; v[n_] := v[n] = M.v[n - 1]; a1 = Table[v[n][[1]], {n, 1, 50}]

CROSSREFS

Sequence in context: A106272 A056423 A056347 * A119132 A073065 A190801

Adjacent sequences:  A122362 A122363 A122364 * A122366 A122367 A122368

KEYWORD

nonn

AUTHOR

Gary Adamson and Roger Bagula (qntmpkt(AT)yahoo.com), Oct 19 2006

EXTENSIONS

Edited by N. J. A. Sloane (njas(AT)research.att.com), Oct 29 2006

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Last modified February 14 20:38 EST 2012. Contains 205663 sequences.