A121811 - OEIS

%I #16 Dec 26 2022 08:33:28

%S 0,3,8,19,46,111,263,622,1473,3485,8246,19512,46166,109230,258441,

%T 611480,1446777,3423112,8099170,19162842,45339771,107275050,253815495,

%U 600533909,1420878484,3361834590,7954186044,18819806248,44528139677

%N This sequence needs a meaningful name.

%t M = N[Abs[MatrixPower[{{0, 1, 1, 1}, {1, 0, 1, 1}, {1, 1, 0, 1}, {1, 1, 1, 0}}, 1/2]]]

%t v[1] = {0, 1, 2, 3}

%t v[n_] := v[n] = M.v[n - 1]

%t Table[Floor[v[n][[1]]], {n, 1, 50}]

%Y Cf. A120471.

%K nonn,uned,easy,less

%O 1,2

%A _Roger L. Bagula_, Aug 30 2006