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A121811
This sequence needs a meaningful name.
0
0, 3, 8, 19, 46, 111, 263, 622, 1473, 3485, 8246, 19512, 46166, 109230, 258441, 611480, 1446777, 3423112, 8099170, 19162842, 45339771, 107275050, 253815495, 600533909, 1420878484, 3361834590, 7954186044, 18819806248, 44528139677
OFFSET
1,2
MATHEMATICA
M = N[Abs[MatrixPower[{{0, 1, 1, 1}, {1, 0, 1, 1}, {1, 1, 0, 1}, {1, 1, 1, 0}}, 1/2]]]
v[1] = {0, 1, 2, 3}
v[n_] := v[n] = M.v[n - 1]
Table[Floor[v[n][[1]]], {n, 1, 50}]
CROSSREFS
Cf. A120471.
Sequence in context: A309537 A126874 A284942 * A370033 A244208 A296329
KEYWORD
nonn,uned,easy,less
AUTHOR
Roger L. Bagula, Aug 30 2006
STATUS
approved